So what makes a boat a trawler?
A trawler is a commercial fishing vessel designed to operate fishing trawls. Trawling is a method of fishing that involves actively dragging or pulling a trawl through the water behind one or more trawlers. Trawls are fishing nets that are pulled along the bottom of the sea or in midwater at a specified depth. A trawler may also operate two or more trawl nets simultaneously (double-rig and multi-rig). The nets are spread apart at the bottom by a pair of "doors," large, heavy plates angled outward to keep the mouth of the net open.
Now if you're talking about recreational boats that the marketing folks stuck the name "trawler" on in a (successful) attempt to fool gullible buyers into believing that their boats had the rugged attributes of a commercial fishing boat, the proper name for these boats is "cabin cruiser." Or as Eric Henning prefers, given the weight of these recreational, waterborne slugs, "heavy cruisers" which I feel is an equally appropriate name.
Recreational cruisers are about as similar to a trawler as my Ford pickup is to a Cat D10. My truck and the Cat both drive around on the ground. That's about it.
Over time, the marketing name for the slow displacement or semi-planing recreational cruiser has become applied to pretty much anything floating on the surface of the water as the owners strive to project, at least in their minds, the attributes of a true trawler onto their (mostly) plastic recreational vessels. So the name trawler is now applied to everything from Bayliner sport cruisers to express cruisers to pontoon boats.
I predict that the next phase of the marketing name game will be to apply the term "mini-trawler" to jetskis and other personal watercraft. I heard a fellow in Bellingham the other day refer to his kayak as a "paddle trawler," so you can see where this thing is going.
We own three boats, a small one and two big ones. The small one is an outboard sportfishing boat. The two larger ones, while each very different from each other in configuration and propulsion, are both cabin cruisers.
We have fairly close acquaintances in the UK who have a trawler. They use it to fish for langoustines off the west coast of Scotland.