The US Coast Guard (USCG) recently released a revised AIS Encoding Guide to ensure that vessel operators enter in their AIS data correctly while in U.S. waters.
According to the new encoding guide:
AUTOMATIC IDENTIFICATION SYSTEM is a valuable navigation safety radio communication tool. However, its usefulness is undermined by the broadcast of inaccurate, improper or outdated data. This Guide is intended to assist mariners in the proper entry of AIS data. Mariners are reminded that U.S. regulation requires that each AIS be maintained in effective operating condition, which includes accurate input and upkeep of AIS data parameters. Continual failure to do so may subject a vessel to civil penalties; to avoid such action AIS users should ensure their system is up-to-date and encoded according to this guidance.
One of the more suprisingly updates is the requirement to include the tow length as part of the dimensions. The guide states:
For U.S. Ship Type 57 (see Table) dimensions should reflect the overall rectangular area of the vessel and its tow.
The extended dark arrows outside of the boat, but within the diagram, represent the tow and its dimensions.
To see the entire AIS Encoding Guide, click the link below: