All I could find on-line as a reference to bottom trawlers was this:
BOATING TIPS -- JANUARY 1996
... for vessels Restricted in their ability to maneuver. This would include dredges, pile drivers, tugs with awkward tows, very large ships, and a few kinds of fishing vessels such as bottom-fishing trawlers.
The Regulations don't include mention of bottom trawling ---but they don't mention revetment mats either
BOATING TIPS -- JANUARY 1996
... for vessels Restricted in their ability to maneuver. This would include dredges, pile drivers, tugs with awkward tows, very large ships, and a few kinds of fishing vessels such as bottom-fishing trawlers.
The Regulations don't include mention of bottom trawling ---but they don't mention revetment mats either