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 setting.
According to tug her
navigation status is "Towing".The tow was 550 m long but Alix just had one setting on their
AIS for Towing.
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)
/Thomas