In spite of the many things that drive us to distraction when it comes to USCG policy letters sometimes the boys get it right. There was a small hitch in the A.I.S. regulations that proscribed tugs with tows ahead or alongside from indicating that distinction via their A.I.S. transponders. They were strictly limited to either being a light tug or towing in excess of 200 meters. Now the realities of A.T.B.s and hip tows have been recognized. The new code “22” is for vessels pushing ahead and A.T.B.s. Up to now we (the A.T.B.fleet) had been broadcasting true “length overall” when underway and in due course received a letter telling us to cease and desist, well now we’re legal. Read on;
http://www.navcen.uscg.gov/pdf/AIS/USCG_AIS_Data_Encoding_Guide-120104_2.pdf
Makes sense to be sure of how long and what configuration you are exactly when confirming your position and configuration to approaching traffic.