My Grand Banks 50 has a LWL of 48' and a beam of 16' giving an "aspect ratio" of 0.33.
Ten years ago I worked on a consulting assignment for a European yacht builder and one of the things we looked at was the beam to length ratio of competing boats at the time. We examined the beam-to-LOA (not LWL) ratio of around a hundred models of leading brands, mostly planning boats (we did not examine "trawlers").
This is graph of the ratio. Each circle is a boat model. As one can see boats tend to become relatively narrower as their length increases. Also there is a great variations at a given length.
http://www.trawlerforum.com/forums/a...1&d=1459167101