I don’t know, but we got a Dutchman here that may explain the “Flyshooter”.
“Twinrigger” presumably means that they have to trawl nets. Whether they can tow both simultaneously is another question. (??)
I know that larger bottom trawlers is set up with two trawl nets, but they shoot one while the other is on the way up with catch to ensure they don’t miss any “on bottom time”.
(Kraken to the rescue??)
PS> To me Pelagic and Midwater trawling is one and the same, but different from bottom trawling.