At Islander we offered both three blade and two blade props for the Freeport 41, the two blade being the recommended prop for the following reason. An option was an indexed prop shaft brake that would align the two blade prop vertically in the shadow of the deadwood. On paper it was pretty cool, in practice it was a disaster.
The problem was it did not incorporate any disengagement safety. It required the skipper to remember to disengage the shaft brake manually before shifting into gear. With a mechanically indexed brake, the result was a number of mangled mechanisms returned to the factory. This could have been easily avoided with a hydraulically disengaged index supplied by engine oil pressure accompanied by a neutral safety switch. It would have eliminated the need for any skipper input.
Perhaps you'll remember my unflattering stories of the in-house Islander chief engineer at the time.
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