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Archive for the ‘nav aids’ Category

2014-08-16 17.47.27

FYI, The Coast Pilot now includes this scan code to its download link for the latest and most up-to-date version for your e-files..

UPDATE by request:  In keeping this method up-to-date I’ve found that the Coast Pilots and Light Lists are available as totally updated pubs available for download monthly.  Now while most of us would love to maintain a purely electronic catalog I’d still recommend keeping the paper version (at least for the Coast Pilot) given the method for corrections described here is not as daunting as the old “confetti party” we were once forced to endure.  The chance that you wouldn’t have a computer screen with which to view the information is slim but it sure is easier (IMHO) to page through a book than a 600 page .pdf.

Captain Victor Antunez asked me to show what the end result looks like to clear up any confusion regarding my method.  In keeping with said request here is the correction for CP#3 as found in the latest NtM 34.

cp3

The next thing to do is turn to the indicated chapter and paragraph and make a note in the margin thus.  Complete all indicated corrections and then close the book, you’re done…….

20140816_203626

The method for the damned Light List is even simpler, download a completely corrected version every month..

The links in this post have been repaired.  I saw fit to re-post this so it can be of use.

I’m going to describe a couple of publication correction methods that I employ.  I believe these methods will save you and your Mates time when it comes to keeping things up to date and offer it up to those of you who wish to comment. First I should emphasize that this alternative method may or may not meet the needs of your situation.  Check with your Port Captain or Compliance Office to be certain that these  methods meet the intent of any company policy or vendor preference.  Here is a link for the Policy letter issued by the USCG allowing the use of electronic copies and archives of commonly carried nav-pubs.  You’ll need to have reliable internet access for this method to work well.

The NtM corrections to the US Coast Pilots and the Light Lists are the most tedious and time consuming chores the mate must accomplish in the course of his day-to-day duties.  I’ve always seen it as a huge effort for a frequently redundant and limited application/resource, resources that aren’t utilized enough in my day-to-day operations to require so much attention.

The traditional method for correcting the Coast Pilot has always been recognized as a poor solution for those of us not equipped with self-updating software and E.C.D.I.S. systems,

“Cut and Paste” is the name of the game and each Coast Pilot  becomes a confetti farm after only a few cycles of the Notice to Mariners weekly editions.

It always begins with a pile of freshly issued hard copies of the Notice to Mariners, a pair of scissors, two rolls of cellophane tape, a pot of coffee, and most of the afternoon watch to bring your catalog of Coast Pilots up to date.  As time goes by with each edition nearing the end of its service life, one windy day is all it takes to blow half of your corrections all over the pilothouse the moment you open the damn thing and all your work is literally “in the wind”.

Then as if that wasn’t enough, this was followed by a marathon session of correcting the many volumes of the Light List at hand using a perfectly medieval method involving perhaps a magnifying glass and the ability to print in miniature like a Gregorian monk rewriting Ted Kaczynski’s Unabomber manifesto.  It could quite possibly drive a man insane, especially after completing about 10,000 corrections  just in time to receive the next newest NtM with 10,000 more.

When you think about it, the corrections to the Light List are really a list of completed work orders for the gang working Aids to Navigation in the USCG.  Every time they move an aid, paint a buoy, or reset a range light it generates a correction.  I mean I do get it, but ladies and gentlemen, these folks are really busy.

First, how do we deal with this cut and paste thing?

The Coast Pilot corrections using this new method are easy.  The NtM has been available online for many years and anyone with a laptop and internet access can download and save a couple of years worth of NtM’s without taking up more than a gigabyte on their hard-drive.  This ability to archive the NtM is a huge improvement over the old method of keeping the butchered hard copies somewhere aboard to show they’ve been utilized.  With this method you’ll never need to print out Coast Pilot corrections.

Now that an archive has been created, the Coast Pilot can be updated using a ballpoint pen and about 25 minutes of your time.  Turning to the pages in the NtM that list the corrections to the CP, note the volume, edition and change number.

1. Open the Coast Pilot, enter the change number as always; Change#, NtM#, your initials, and the date the change is being entered.

2. Next find the page and paragraph of the correction listed in the NtM.

3. In the left margin of the cited paragraph, write the NtM # in ink and repeat this practice for every correction available for the CP.  For example, you’re using NtM 25/09, the note in the margin should read “25/09“, that’s it.  Also, remember that a NtM may contain numerous “change numbers”, be sure to enter these properly as you correct each CP.

4. Now close the book.

Since you’ve changed how you correct this book, you must change the method in which this book is used.  Now the archive you’ve created must be maintained for as long as the edition is valid.

If you find yourself referring to the CP for information and come across a notation you’ve made in the left margin you know to refer to the NtM archive and must seek out and read that particular NtM (25/09) for the applicable update for that specific paragraph.  As you’re doing that you’ll note a definite lack of confetti present, no matter the age of the book.

The Light List ( the list that never ends) is even easier.

The Light List does not lend itself to correction easily using the old Gregorian method.

It’s wickedly tedious , but the method to update this publication needn’t be so overwhelming.

The NtM is not the publication of choice for me for correcting the Light List. What ‘s that you say? Well, the USCG publishes a cumulative summary of corrections for each volume of the LL.  Basically, every correction for Volume 1 of the Light List is compiled into a regularly updated archive available for download and saving just like the NtM, but each archive is dedicated to its respective volume.  From the date the volume is published to the most recent NtM, each volume’s corrections are compiled as they appeared in each NtM.

So, I can go to the NavCen website and download all of Light List Volume 1 corrections and save it each month as I can for every volume of the Light List offered by the National Ocean Service and USCG.  The archive found on the update page always carries the same name for each volume number unlike the Ntm which necessarily increases (01/09 to 52-/09) as the weeks go by.  Volume 1’s summary will always be named V1D01.pdf.  When you download the newest archive it will prompt your browser to ask if you wish to overwrite the old file and of course you will select yes.  You now have the latest correction summary for Light List 1 since it was published.

1. At this point, you only need to make one mark in the Light List and that is to note the NtM# that your archive is current with in the record of change in the front of the book and after you’ve done that, you can close the book.

Now we dip our toes into the 21st century;

2. If you find yourself referring to the LL, the same method as always is used to identify any aid, by its LL#.  Once you locate the aid you want, (or the place where it should be listed), the original “date of publish” info is all you have.  How do you know the information is current if there aren’t any physical corrections in the book?

The summary of correction archive contains a copy of every Vol1 correction page printed in the NtM since the Vol. 1 publish date from low to high.  In the case of LL1, from 51/08 at the bottom of the list to 25/09 at the top.  It should be noted that there may be multiple corrections  for your query, check the entire summary for the aid in question.

3. Once the aid in question has been found in the LL, the archive is scanned from the bottom to the top of the list for the same LL#.

3a. If you don’t find the LL# for the aid your looking at, the book is the latest information available for that aid.

3b. If you do find the LL#in the archive, you’ll need to scan the entire summary for any other incidence of that number.  If you have found the LL# of your aid in the summary, that information will be the most current and correct.  You need to remember as well that new sub-sets may have added, so a scan above and below the specific aid’s LL# you’re referencing is in order.

So, instead of spending hours of your life writing corrections into this publication, you’ve spent five minutes scanning an archive to find what you need.

Take a look at this method, if you would like to discuss it further, drop me a line.

Light List Summary Links;

Volume 1 First District, Volume 2 Fifth District, Volume 3 Seventh District, Volume 4 Eighth District GOM, Volume 5 Eighth District WR, Volume 6 Eleventh DistrictVolume 7 Ninth District,

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sha1406032813sha1406033434sha1406033401I’ve been working in the G.O.M. for the last 16 months or so and regularly find myself making that long transit from the Dry Tortugas to the Southwest Pass of the Mississippi River.  The trip is more or less a great circle extending 400+ nm.  The first few times I made the crossing I noted that I would have an extreme “crab angle” due to the influence of the current known simply as “The Loop” aka a parent source of the Gulf Stream.  Sometimes I’d be steering upwards of IMAG162815 degrees into the current in order to make good my charted course and struggling to make any real speed.  Sliding across the Gulf is the rule.

There’s little doubt that this is old news to the guys who have been working the gulf for years, but it was a real surprise to me.  I mean, I expected different, but not to this degree.  Banging up against the Gulf Stream makes for slow going, no real mystery there.  And running with the stream is amazing in that your speed exceeds anything you thought the boat could do…but the loop?

The “Loop” is a current in the Gulf  of Mexico and flows at greater or lesser velocities as the seasons change.  It is known to meander widely and is formidable enough to knock more than 3 to 4 knots off your speed.  Meander is a gentle way of putting it, one watch you’re cruising nicely, next you’re wondering if the wheels fell off…  It’s seems to be all over the place, but with satellite imagery and telemetric magic it can be tracked.  And if it can be tracked it can be planned for.  Soooo for  those of you who know all about this, need read no further unless you’d like to proof my work.  In which case I will gladly accept any additional clarifying data you’d wish to provide.

The information one needs in order to visualize and to take advantage of / or steer around this current  has been available, but the resource (available in the form of “pilot charts”) only gives a general overview of the current by the month.  Honestly, I didn’t find them all that helpful.

My colleague gave me this link that provides just the kind of data you can use.  The site is paid for by our tax dollars and in my opinion money well spent.

You’ll need to make certain your security settings in your browser allow java applets to run.

The initial page gives you the overview which you can select a geographic area and what you’d like to see.  If you just want velocities, click it.  If you want to save the data as an image, select .gif format.  The smaller the geographic area, the easier you’ll be able to interpolate the lat and lon grid.  (I use MS Paint to overlay the more detailed lat/lon grid, it’s a bit tedious but yields an reasonably accurate grid to pick off waypoints)).

Note the red grid over the gulf.  you can resize it as you wish and pick the day average as well.  I usually use a 3 day average.  Once you’ve made your selection choose .gif if you want to save the image.  After that, you can eyeball the route you want to take and then identify the waypoints you’ll need to hit to go around the adverse current or to take advantage of a following current.

 

gom site

This will assist in selecting a course around the higher velocities and hopefully save some time on your next transit.  Sometimes a few miles out of the way can save more than a few hours, an all important option when it’s close to crew change.  After all that is the most important consideration….just sayin’

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As you may have read in previous posts I wanted to try the “online experience” for my radar renewal.  It did not go well.  I signed up paid $225.00 and received my study material and then proceeded to work myself back up to a passing proficiency for rapid radar plotting.  I took a couple of months, made an appointment at the nearest Prometric Testing center and believing I was ready, scheduled and sat for my renewal.   All went well up to this point.  The facility is clean, well organized and strict.  I arrived early and was processed quickly.

The exam was straightforward enough.  Once you get settled in at your exam station, the computer program is loaded and a timer promptly begins with your radar scenario.

There was the first part of roughly ten questions regarding theory and then the plots.  I had no difficulty with theory and scored 100%.

You get two shots at the plotting section.   It’s a normal three target screen, you need only identify the “most dangerous target” and proceed with your plot.  I must add the timer is a bit unnerving.  If you fail the first time it gives you the opportunity to select and proceed with a second chance/ different set of plots and you fly or fall at the end of the scenario.

I failed both my attempts on the exam and felt more than a bit embarrassed seeing as I had never not passed what we’ve all come to see as a less than useful skill since the advent of A.R.P.A. and modern radar systems.

I must admit that the failure was likely my fault due to my time management (or lack thereof) and perhaps a careless error.

The plots are “time sensitive” and you’re only allowed three minutes to solve for NTCPA and new course.  I overran the time limit first time out.  After the exam I noted in the instructions on this particular exam that there was no specific time for MX expressly indicated.  The instructions for MX or “time of execution” were included in the practice instructions but absent in the actual exam instructions.

This isn’t an excuse, since after the fact I  found the instructions in the practice material clearly indicated that the exam’s execution point was to be at 12 minutes.  I missed that somehow.

Okay, so I failed.  I was more than a bit upset, I have never failed this recert but I guess there’s a first time for everything.

No amount of post failure negotiation was sufficient to convince the proctors of the center to help, and the online school was adamant that in order to retest I’d have to pony up another $225.00 and reschedule.   I didn’t elect to take them up on it.

Instead I called SUNY Maritime and scheduled my one-day renewal at a “brick and mortar ” school.  I paid the fee ($325.00) and practiced the material they sent and showed up in the Bronx for the recert like I’ve done in the past.

The experience was easier in that I had an instructor on site that understood the material.  He could see which of us in class were comfortable and possessed the skill set and helped guide those who were a bit shaky during the morning practice session and boosted their confidence level.  That alone means a lot to anyone who’s uncomfortable in exam situations.

You’re not handed the cert,  it’s challenging and you earn it.  But that said, having the class in a place where it’s a familiar curricula helps.  Online courses are fine, but you’re strictly on your own at the center.  After you are scanned, frisked and asked to empty your pockets no one can or may assist you in any way.

I passed SUNY’s recert program as expected and left to deal with the gauntlet that is the NY area’s traffic to get home.

In closing, if you’re absolutely certain and speedy with rapid radar plotting you should give the online experience a go.  If you’re like me, go to a school where an instructor can kick you back inside the lines of competency and get you through this “every 5 year P.I.T.A.”.  I have a couple more times I have to submit to this ordeal and you can be sure it will be at a “brick and mortar” school from here on.

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It’s old news now, for all intents and purposes L.O.R.A.N. is dead.  Aside from the arguments for or against shutting down the system, it’s fait accompli, the deed is pretty well done.

I’ve read the articles filled with the hand wringing and gnashing teeth of how the system should be left in place as a back-up in case of whatever….hey waitaminit,  what “backed up” L.O.R.A.N.?  Should we set up radio beacons again and fire up the old  R.D.F.?  Have you seen a working R.D.F. on anything afloat besides a vintage Russian Spy Ship lately?

In fact, most coastal charts don’t have the grid anymore unless it’s a special order or an antique.   If you still have a L.O.R.A.N., how often have you used it since adding G.P.S.?  I haven’t seen a L.O.R.A.N. unit aboard for at least 8 years, I don’t miss it.   It was easy enough to use the TD’s but once G.P.S. was in the game it was the hands down winner.  Yes we depend on it, yes we move bigger stuff with closer tolerances, it was a natural progression.

Could it be that our chart-plotters and all the sophisticated A.I.S. coupled devices we use are now one solar flare, a spilled cup of coffee, or government whim away from non-existence?

Is it possible that our navigation technology, so intimately wrapped up in those tidy little G.P.S. receivers, may fail or be taken away at the worst possible moment?    Well duh…  that’s always been true, as with any electronic aid.  We’ve talked about this before.

You’re not supposed to be relying on any one aid for navigation, no matter how slick it is.   The nav-discipline you exercise while underway should use everything at your fingertips.  Some more than others, but none more than your ability to recognize the limitations of each tool.  When it comes to your piloting discipline, no battery back-up or antenna is required.

You need an up-to-date chart, a decent stabilized radar, a good grasp of D.R. plotting, and a sharp pencil.  Plotting D.R.’s and detailed voyage planning are just prudent procedures. Professionals prepare a full fledged voyage plan.  The voyage plan by definition is a working document and it is adjusted as the voyage progresses.

The idea of plodding ahead without keeping track of where I’ve been and where I expect to be has not entered the equation since detailed voyage planning has been made part of our operational procedures.  Whether I put a mark on the chart or make a note, there is a record of where I’ve been within the last 30 minutes to refer to.  Be it a landmark, bearing and distance, L.O.P., or radar range and bearing.

Sooner or later, something will stop working as it should, and even if every layer of “e-redundancy” fails, one can still have enough recent data to discern a decent estimated position when all of the e-toys fail.

It’s easy to be lulled into a false sense of security when you’ve got the magic box telling you what you want to hear, even when your eyes would tell a different story.   With electronics, chart plotters, and A.I.S. in agreement, few would doubt their position, but we shouldn’t be missing that healthy dose of skepticism.  Scanning the instruments and looking out the window are practices hard-linked to safe navigation especially while piloting. To rely completely on any one tool means you’re shit out of luck when that tool fails.

Devices go out of whack for the strangest and sometimes the simplest reasons. The story and subsequent investigation of the cruise ship Royal Majesty’s grounding on Rose and Crown Shoal off Nantucket was reported to be partly the result of the navigation officers assuming their electronic information was gospel.  That assumption contributed to the events that turned a routine trip into a nightmare.  Among the critical things they missed was the alarm on the master G.P.S. unit indicating that it had switched to D.R. Mode (due to a faulty antenna).  Even with a L.O.R.A.N. unit (which they apparently ignored) integrated into their navigation suite, they went aground 17nm off course.  Okay, so they weren’t piloting, but they had an operational L.O.R.A.N. and didn’t recognize their navigation error until they were making lobster salad on Rose and Crown.  A couple of L-plots may have clued someone in.

“Things to consider“:

1. Fathometers:

While stopped with no way on, a fathometer will only tell you what’s under the transducer at that moment, add a few knots of speed and you’ll be able to identify a trend (shoaling or deepening), but prop-wash turbulence from another vessel (or your own), or choppy seas can obscure accurate readings.   Fathometers generally display the depth under the keel as the default display.

2. A.I.S.:

An A.I.S. transponder can and will display incorrect data if it hasn’t been set up or updated properly.  There’s no way to be certain the transmitted A.I.S. data is correct unless you confirm it the old fashioned way, plot it.  Determining a C.P.A. using only A.I.S. data is a fool’s errand.

3. G.P.S. Chartplotters:

Chart plotters rely on static data for charts(vector or raster) and some can be updated online with the latest corrections, but even if you have a “state of the art” device,  your chart plotter may not reflect the most up to date bouyage or navigation information.  It isn’t gospel…..and we all know how Windows based systems can be, shall we say, fickle.

4. Radar:

Radar is a simple concept of reflection.  It is still in use as a critical and necessary tool while R.D.F.’s, Omega, and L.O.R.A.N. (both A and C) have fallen by the wayside.   It’s limitations are mostly related to signal attenuation, clutter caused by sea-state, precipitation, or user error. Since radar is a “line of sight” device,  it’s limited by it’s geographic horizon.  The biggest problem with Radar is mis-interpretation of the data presented, that’s why we’re required the radar course for our licenses.  See Big Bayou Canout.  See Andrea Doria.

Radar navigation is more than just plotting vectors for collision avoidance and identifying landmarks by their profile, it’s a skill that backs up our piloting and position fixing.  I can honestly say that for my work,  collision avoidance plotting on paper is way down the list as far as how I use radar in my “day-to-day”.

Targets can be missed if they are low to the water, have non-metal reflective surfaces, or are over the horizon.  The distinction of this device is that it updates with every swing of the scanner, BUT unless you are stopped and making no way, it tells you where you were, not where you are.

For coastal navigation and inland piloting, radar fixes are useful tools and are not dependent on anything except the skill of the operator, a gyro compass, and the power supply.  A stabilized display that produces a bearing line using the E.B.L. function (electronic bearing line) is a tried and true method of taking bearings.  Two good bearings to fixed objects ashore at or near 90 degrees apart = a fix.  No G.P.S. info or pelorus is necessary.

radar fix generated by taking a range and bearing to a known fixed object (lighthouse, beacon, point of land, or dock) or swinging a couple of arcs using the V.R.M. gives us a pretty accurate indication as to where we are.  From that point (rfix) we can lay off our planned course and speed on the chart and have a reliable graphic representation of our position in relation to all around us.  Plotting using this method is a solid means of position fixing.  But it’s only good at the moment of the fix, introduce any change and it isn’t accurate any longer.  Those changes include but are not limited to, speed of advance, changes in current, wind direction, and time. After that it’s a D.R Plot until the next fix.

Parallel indexing is another, frequently overlooked function of modern radar.  It’s a simple method of determining the “set” on or off a coast or hazard.  It enables a quick visual reference to the user without making any calculations, if a target or hazard is inside the index line, we’re closing, outside we’re falling away.

Radar may not be as sophisticated as the new plotters and it takes practice, but it’s a good basic tool.  I regularly deal with multiple targets, large and small, going at different speeds and courses in close quarters.  Sometimes one needs to be a bit clairvoyant in order to make any sense out of what is on the screen and what those targets have in mind.  It’s up to me to know, as best as I can, where I am and what I can do to avoid getting too “up close and personal”.  The best defense I can have is using every device I have at hand along with a good pair of eyes and the sense to use them.

Using radar as a position fixing aid should be a regular part of the nav-watch’s procedures.  When you have the luxury of taking a certain route regularly, the picture on the display becomes familiar enough to pick out subtle differences between the buoys, shoreline, and potential traffic.

I’m aware that at any moment my boat or the one I’m approaching could suffer an equipment failure that will impact my decisions. Maintaining one’s situational awareness includes keeping a solid “plan b” in mind.

5. E.C.D.I.S. (Electronic Chart Display Information Systems)

For the most part, these devices are on ships rather than tugs due to their high price.  They’re supposed to be the ultimate in “networked navigation devices”.  Radar, A.I.S., G.P.S., fathometer, chart-plotter, A.R.P.A and more, are all rolled into one.  If there are two complete and independent installations on board, the vessel can sail without a paper chart catalog.  The database can be updated with the click of a mouse, but it’s still something that needs to be treated with a grain of salt.

And if one needed any more proof,  the fallability of electronic aids is illustrated quite well by a notice published by the I.H.O.  The way chart displays used in E.C.D.I.S. are encoded has been determined to have an error that could cause grave consequences.  The  depth contours on some charts are improperly encoded making certain hazards invisible (specifically depth contours), prompting NOAA to insist users use the “all data” setting during their planning and monitoring of voyages.   The entire catalog will now be inspected for more of the same.  The sexiest technology can bite you on the ass even if you’re following proper and professional procedures.  It pays to remember the basics.

So the issue that G.P.S. is a lot of eggs in one basket, yeah I get that, but we should be keenly aware it’s only a small part of the array of devices and skills we have at hand whenever we get underway.  Being aware of the consequences of relying too heavily on any one aid and backing up navigation procedures with good basic practices will always serve you well.

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hell-gate-rr-bridge

Hell Gate Railroad Bridge looking west, photo by Capt J.T. Brucato

This piece doesn’t intend to provide a comprehensive method for dealing with transits, it’s offered in the hope it will give a bit more background and glimpses of how  professional mariners deal with their day-to-day operations and how this transit is approached.  A little Hell Gate history would be in order for those with  an interest in the way things come about.

It was all about “commerce” as you might have guessed.  I found this article online and I wish I could name its author. It does a terrific job of filling in the blanks on this bit of New York Harbor and how it was made into the lifeline it is today.

During a spring tide cycle the velocity for the ebb current can easily reach 5.0 knots or more depending on prevailing weather conditions.  Wind from easterly weather will tend to increase tidal ranges and flow and cause tidal changes to occur later than expected,  extended periods of west-north-westerly weather will hold levels below normal and cause tidal changes to occur earlier and with less velocity.  It’s just a function of geography and wind direction how the NY Upper Bay and Long Island Sound respond to the effects of wind.  Anyone who has followed the hurricane watches on the Weather Channel can understand the way water piles up from the influence of an onshore breeze.

harbor-wind-se

When you’re eastbound, the eddies and set experienced in each part of the transit will be slightly different but predictable each time one makes transit at different stages of tide and current and weather.  The East River Deep Water Range is a good example.  The U.S. Coast Pilot #2 clearly relates that on any given tidal cycle the “Gate” is going to have currents usually in excess of 3.5-4.0 knots.  It offers enough detail to make one aware of the geographic and hydro-graphic facts, but leaves the finer points of piloting this body of water to the paragraph recommending “pilotage services”.  Hell Gate is in the tidal strait known as the New York East River which connects three major bodies of water; The New York Upper Bay, Long Island Sound, and the Hudson River via the Harlem River.  The semi-diurnal tidal flow can reach speeds of up to 5.0 knots depending on the lunar cycle and prevailing weather.  The project depth from the Battery to the Navy yard is 40′ and then 35′ to Execution Rocks,  the range of tide is 4.6′ at the Battery, 5.1′ in the Gate, and more than 7′ at Execution Rocks.The  tight channel and rocky shore makes for an unforgiving environment for piloting errors.  His Honor the Mayor won’t need to watch the six o’clock news to see when someone has made a mistake, since his official residence (Gracie Mansion) overlooks the river at the best place to witness any transit.The waterway’s orientation is generally Northeast-Southwest, but local mariners usually declare their intentions as “Eastbound for the Gate, or Westbound for the Battery”.  The currents run close to the “Narrows”  but for a small time difference.  Most tugs and tows transit at or near slack water for safety’s sake.  Some ships and large A.T.B. units will make their transits up 2 hours before or after the slack in order to avoid high concentrations of traffic.

The Influence of Wind;  So it follows; if there has been an extended period of easterly weather, one can expect tides to be above their normal levels and currents to be running stronger than predicted.  Westerly wind will cause tidal levels to remain below normal and cause tidal flow to begin earlier than normal with less velocity because of reduced volume.  Unless this westerly weather is directly following a storm like a “Nor’easter”, in that case as the wind veers westerly, the ebb current can be expected to be dramatically stronger than predicted.All of this adds up to a tidal strait that will test the skills of anyone who wishes to pilot a vessel east or west.  Understanding how things actually work will save a lot of heartache.Flood Current Transits; The flood current runs from the Battery and the Buttermilk towards Long Island Sound.  It travels up along the shores of Williamsburg,  Brooklyn and along the east and west channels on either side of Roosevelt Island.  The flood current enters the western entrance of the Harlem River from the Hudson River running south into the East River and meets the main flow at and around Mill Rock.  Then as it all mixes at Hallet’s Point it runs east toward and between the Brother’s Islands and out to the Sound.

The phenomena known as the “Spider” is a swirl off the Battery that results from the confluence of the Hudson’s volume and the East River’s flow within 1.5 to 2 hours before and after the change of current.  (From the Coast Pilot #2;  ) In the channel northward of Governors Island, cross currents may be encountered. During the first 2 hours of flood in this channel (eastward), the current in Hudson River is still ebbing (southward). In the first 1.5 hours of ebb (westward) in the channel north of Governors Island, the current in Hudson River is still flooding (northward). At such times large vessels must take special care in navigating the channel. It is reported that the most dangerous time is about 2 hours after high water at The Battery. At this time the current is setting north in the Hudson River and westward from the East River. The effect on a large vessel coming from southward and turning into the East River is to throw her stern to port and her bow to starboard, thus causing a sheer to starboard toward the shoals off the north end of Governors Island. When coming from northward in the Hudson River the same effect tends to prevent the vessel from turning and to cause her to overrun her course. These cross currents are known locally as The Spider.As the East River current slacks, the Hudson River current at the Battery is still running fairly strong.  The later current changes in the Hudson allow this swirl to develop and has the effect of setting the stern once the bow enters the shadow of Governor’s Island and slower flowing East River. It’s in the worst possible place since there is a rather impressive shoal just north and south of the range line and must be allowed for when shaping up to enter the East River Deep Water Channel.  It will affect a deep draft vessel (15 to 30’of draft )by trying to spin her as she sets up on the range.  It’s strong enough that it must be given due regard and anticipated for its effect .  Generally a bit of rudder will overcome the tendency to spin off the range, the vessel will slide somewhat onto the range and steady up as she passes Whitehall ferry racks.

Tugs with stern tows “up short” will generally use the Deepwater Channel to enter the North River off the Battery in order to pick up their charges alongside of the Colgate Clock in preparation for the transit to their eventual berth.  Fast ferries, large and small are present at all times of the day as well as small vessel traffic, tour boats, and dinner cruises in and around the island of Manhattan.

Flood Current Transits Eastbound;

The effect present as one enters Buttermilk Channel off the north end of Bay Ridge Anchorage is a well defined slide that sets NNE as the vessel turns in on the Buttermilk range which tries to force the vessel towards the SW tip of Governor’s Island and its piers on the south side.

On approach to Atlantic Basin in the Buttermilk Channel, there is a well defined “set” that begins to affect the tow as it is passes the Old Brooklyn Piers. The current will cause the tug and tow to sag toward the pier-heads under the it’s influence and require adjustment to keep the tow from clipping the ends of the piers as the Brooklyn Bridge is approached.  This will become apparent once the tug and tow are just past the ends of piers 7 and 8.  When inbound on the Deepwater Range, this slide will be a consideration as the turn for the Brooklyn Bridge is set up.  The confluence of the currents and the shoals on the eastern end of Governor’s Island  and off the Battery are only the first set of challenges the transit has to offer.

As the turn under the Brooklyn Bridge is approached the flood current’s “set” will now force you toward the Manhattan shore and increase the over bottom speed.  There is also a local anomaly that affects radio transmissions here, one must take care to make a “Securite'” call well prior to passing the Brooklyn Bridge and as soon as possible when clear of the Hudson Ave. powerhouse to warn traffic that may not have heard the initial call.  This is also where V.T.S.N.Y. requires vessels to switch over to their next  zone frequency (channel 12 vhf) which is monitored until clear of the Throg’s Neck Bridge.  The next big turn is Corlear’s Hook opposite Wallabout Bay and the Brooklyn Navy Yard as you set up for the transit under the Williamsburg Bridge.  The flood current set is now strong on the Brooklyn shore and requires a fair amount of rudder to correct and end up in the middle of the deep water and stay on track for the Poor House Flats Range.  On large deep draft units, this is generally a controlled slide as opposed to a turn.  Small westbound tugs and low horsepower units still hug the Manhattan wall (westbound) at this turn to try and escape the main flow of the current.  It usually runs just a bit slower along the wall and if you were shallow enough, you could avoid 10-15% of the current’s velocity.  Once clear of the point the practice was to cross to the Hudson Ave on the Brooklyn side to utilize the current’s shadow there.

As the vessel advances past the old Domino Sugar dock and North 1st Street approaching the Poor House Flats buoy and range, the current tends to set toward mid channel and then along the channel.  Turning onto the Poor House Flats range is an exercise in timing since the vessel must bring the current onto its port quarter and slide onto the range line and steady for the turn at E. 34th Street.  This is a critical turn for deep draft units since the buoy marking the turn at the southern tip of Roosevelt Island sits just south of a shelf that extends into the channel with less than 25′ of water over it.  The turn at the U.N. building requires one be prepared for the set of the current toward Manhattan as she shapes up for the Queensboro Bridge, (locally referred to as “The 59th Street Bridge”).  Here the current runs true with the channel up to 74th Street.  There is a section of turbulence that sets up during the strength of the current in the vicinity of the bridge, an upwelling caused by the structures of the Mid-Town Tunnels buried in the river bottom can be fairly intense.  As the north end of Roosevelt Island is approached the velocity of the current will notably increase as the channel narrows and creates a bit of a venturi effect.

Meeting in the Gate anywhere near maximum current time is a very bad idea, there’s precious little room to play with and you’d be meeting each other in a turn with a swift current.   There are just too many points of failure to accommodate a safe transit.  Even if the current ran with the channel the situation would be too unwieldy to handle with all the variables.  That doesn’t seem to prevent plenty of “deep draft sailboats” during the season, who fail to understand that it’s not healthy to occupy the middle of the channel when 25,000 tons of steel and fuel are headed directly at you.

Once a large unit has passed Belmont Island off the United Nations building near East 34th Street, it is committed to the transit.  There isn’t anywhere wide enough to turn around and the strength of the current would generally prohibit stopping without a substantial assist tugs in attendance.

Once committed she must maintain her steerage and stay mid channel until reaching the 74th Street Powerhouse.  It is not advisable to advance eastbound beyond 74th Street with the flood current if one expects  to be meeting westbound traffic near the Gate.  West-bounders “bucking tide” are at their worst for getting out of your way.  Unless you’re talking about a ship or other large  and high horsepower unit, they are using every ounce of horsepower to overcome the current with little left for making any significant headway.  On a fair current this waiting game should take place well south of the Poorhouse Flats buoy or better still, hold in the upper bay and time the transit closer to slack if a lot of traffic is returning westbound.

The turn at Hallet’s Point is the initial turn into Hell Gate proper and is usually “shaped up ” by finding the center line of the Tri-Boro Bridge and sighting a safe distance off Negro Point and then splitting the difference for the left turn under the Tri-Boro and Hell’s Gate Rail Bridges.  Here’s where most tugs and tows can suffer a push gear failure should they misjudge the turn.  If there is a significant amount of  flood current left before slack, the eddies flowing from the Harlem River (from left to right approaching the point) will certainly slide the tow towards the Astoria side of the river once the left turn under the bridges is made.  The port side is now broad to the current and its influence will require the helm to increase to a hard right rudder with a gentle increase of throttle until the tow has advanced past Negro Point and out of  the cross-current.  If “hard right rudder” is applied  too quickly or if  the throttle is slammed to the stops, the starboard push gear will be taking a huge load and it’s possible that the gear could part and cease to be of use as the tow falls out of shape towards the rocky shoreline of the Astoria Wall.  Safety lines on either side of the tug may be of some effect but the leverage of proper push gear will be lost.    Once the Hell Gate Railroad Bridge is overhead, the tricky part is pretty well done.

Lining up “The Brothers” is easy and the turns will widen as the waterway opens up.  The deep draft route necessarily will be north of the islands, only small shallow draft tows go between.  The rest of the transit will pass the last oil terminals on the waterway when passing East 138th St. to 149th St in the Bronx.  La Guardia Airport and Riker’s Island, then the Whitestone Bridge and S.U.N.Y Maritime and the Throgs Neck Bridge.  Once clear of Throgs Neck there is a hard left turn up towards City Island and past Stepping Stones Lighthouse.  This lighthouse marks a 24′ shoal that extends west of the light itself, recommended clearance to allow  for this outcrop would be a radius of at least 1/4 nm. as the turn for Hart Island and Execution rocks is made.  The deep water is available on both the north and south sides of Execution Rocks.  It is well marked and smaller units can and do stay to the northern route during stiff northwesterly weather to enjoy a lee from the Connecticut Shore.

The biggest issue that will be encountered at this part of the transit will be during the recreational boating season which kicks off just before Memorial Day when the area is thick with small motorboats and sailboats right through the summer and into late autumn.

Ebb Current Transits Eastbound;

Making a transit against the ebb current is a common practice.  Eastbound vessels heading through to Long Island Sound will experience the full force of the current as they approach the major turns and the upper end of Roosevelt Island and Hell’s Gate itself.  There are several significant parts of this transit that bear further explanation.

The Buttermilk and Deepwater Channels spill into the upper bay and Hudson with substantial volume but generally speaking, the currents are running with the trend of the shoreline and easy to manage.  Like vessels working the Western Rivers, the vessel running with the current or fair tide is considered the stand-on vessel.

If your vessel is “stemming” or “bucking tide”, you’re expected to hold back in various places along the way and allow the stand-on vessel time to clear the big turns or the tight spots in their transit before you continue eastbound.  To impede their transit would be an invitation to disaster.  The best hold points are in the straightaways off the Domino Sugar dock and up to just south of the 59th St. Bridge.

The Back Eddy between Roosevelt Island’s North Tip and Hallet’s Point;

There exists an eddy that sets up during the ebb cycle just below Hallet’s Point at the north tip of Roosevelt Island that demands the consideration of any unit towing, pushing ahead, or towing alongside as it enters the Gate.  The back eddy begins to affect the eastbound unit as it approaches the north end of Roosevelt Island and will add 1.5 to 2 knots of S.O.G. (speed over ground).  This eddy’s influence will disappear quickly as the tow reaches the turn at Hallet’s Point and the speed gained will quickly diminish.  What develops at this point is the current is now on the starboard bow and the port quarter at the same time, this will try to spin the tug and tow to port.  There is a real possibility one could end up sheering to port and into serious trouble as the current will force the whole unit towards the shoals of Hog Back.

Towing astern in the back eddy; the tug enters the main flow at Hallet’s Point but the tow is still carrying (up to 2 knots) more speed and can now run over or trip the tug as it follows the laws of physics and the tendency to stay in motion.  The current can easily sheer the tow away from the tug, coupling its greater speed and mass to endanger the tug.

The method for avoiding this situation requires the tug towing astern to stay in the ebb current and outside the edge of the back eddy as much as possible.  This obviates the need to worry about increases and swift losses of speed since the tug and tow will remain in the ebb current and see no dramatic increase in speed due to the back eddy.   The idea is to avoid the “kick in the ass” the back eddy provides if you’re towing astern.  It wouldn’t be prudent to play with that bit of current.  New mates and deckhands alike are impressed by the amount of headway the eddy will impart to the tow, but they should never forget how quickly the counter-current at Hallet’s Point takes it back.   By the very nature of the ebb current transit, there isn’t a whole lot of throttle left to use if things start getting “squirrely”.

The “Current” Myth;

It’s a well circulated local story of how the current in the Gate makes it nearly impossible to hit the wall at 96th Street off Gracie Mansion when westbound.  The story has been told a thousand times how untended scows broke away from their moorings and drifted unscathed through the Gate as if they magically steered themselves through.  The story goes “you shouldn’t worry about hitting the wall since it was impossible given the current flow and depth of the water”.  In my experience I have personally witnessed a couple of small scows do just that, but they did it on the flood current and they had an assist from favorable breezes. And of course, nobody says what happened after the magic scows cleared the Gate.

The fact is you CAN hit the wall.  If your transit is at the strength of the ebb current westbound, and you fail to judge your turn approaching Hallet’s Point correctly, you will find yourself sagging into the 96th Street wall wishing the local legend was true.  Depending on your draft, wind, and speed, you will most certainly hit the wall and then bounce across the river to hit Roosevelt Island’s north end for good measure as the current swirling behind Mill Rock throws you across the river.

If your transit is set up for an eastbound flood current transit, the Astoria wall is your likely stop if you suffer a steering failure or poorly timed turn at Hallet’s Point.  The current will first force your tow off Hallet’s Point and then sideways to the Astoria side as you try to steady up under the Tri-Boro Bridge passing Negro Point.  It gets even more exciting when the starboard push wire let’s go and you’re faced with a possible hobbled wheel and an imminent grounding.  Add a deep draft sailboat in mid-channel and your day is complete.

A few years back, a large Turecamo tug was towing an empty 130,000 bbl. barge astern, westbound, when a towing gear failure occurred just as he was steadying up off 96th Street.  The barge’s connection to the tug was severed and a light 130,000 bbl “beastie” careened into a  “6 oil” barge  (heavy industrial fuel, nasty stuff) that was moored at the 74th Street Powerhouse.  The runaway peeled the moored unit off the dock along with the dock’s cargo manifold.  It’s a lucky thing cargo ops were done for the day.  Now two barges are drifting downriver scraping and banging along the Upper East Side’s promenade until both were finally corralled and pinned to the wall near the old 63rd Street Heliport.  The master on the Turecamo boat got hold of his runaway and luckily another tug that was in the vicinity captured the runaway 6 oil barge before it could inflict any dramatic environmental damage.  I was almost part of that story but for the fact the master of the Turecamo tug made a timely radio call in the calmest voice informing all that he lost the tow and was going to try and recover it.  I had to call a unit ahead of me that had just passed the Brother’s Islands asking if I was hearing things.  The unit ahead said it was no joke and he was turning around to wait until things settled down.  He “rounded up” off East 138th Street, and I “rounded up” off Hunt’s Point.

The East River is a handful and we necessarily spend a good deal of time making certain new mates understand and respect its characteristics.  There’s no room for error and it’s a very “New York Harbor” thing to learn.

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cws

This link was sent to me as the answer to all your New England Weather needs and then some.  It covers almost anything you can think to ask about the present weather picture.   Take a look and bookmark it as a useful resource.  Bandwidth warning, this page has a lot of graphics and will take some time to load, be patient.

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