On a sunny day with a light northerly breeze in the middle of the Bay of Biscay, crossing the "Highway" between the traffic-separations off Ushant and off Finisterre, I came upon this tug with the navigation
status of "Reserved 11".
Calling up MCS Alix on VHF
, they were kind enough to explain their AIS
According to tug her navigation
status is "Towing".The tow was 550 m long but Alix just had one setting on their AIS
So "Reserved 11"(ais.cpp line 149) should be changed to reflect this.
Marinetraffic.com describes it like this:
11 = power-driven vessel towing astern (regional use)
12 = power-driven vessel pushing ahead or towing alongside (regional use)