I always assumed a law of diminishing returns - 2 blade to 3 blade to 4 blade+ - and that the sweet spot for non-electric trawlers was 3 or 4 blade.
I class electric differently due to the ability have usable torque at any rpm from 1 upwards, and trawlers differently due to speed.
There seems to be many trawlers who cruise at 6-8kn but have a possible top speed of 14+, and would seem to benefit from two entirely different props to maximise both options. Since that may be changing pitch and number of blades, I have no idea how one could do it
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