This is a question that came up for me when I replaced my old Yanmar
on my 26 foot keel boat
had left turn rotation whereas the new motor
is right. Yet another unexpected (although obvious, with a tad of forethought) cost in the repower
. And a prop is a significant expense.
I choose a big 3 blade fixed, even though I do race
the boat. I wanted the prop to be maintenance and trouble free. I accept that she doesn't back quite as well and it has some prop walk. But I don't spend my day sailing
backwards. And the prop walk is often useful and quite manageable. And it was the cheapest option by a large chunk of money
at the time.
And in my experience it was quite common at the hard stand to see boats with folding props having to be lifted because they'd jammed in either forward or backwards position. Out of a fleet of 200 boats at the marina, it seemed perhaps every 2 or 3 months a boat would have issues.
But most of all when the weather
caves in and I need to get home with my grand kids
is quickly as possible the 3 blade will do the hard work
. It also gives good grip in the water, so at a fast idle she sits on 3 knots. It gives me the capacity and confidence to tow boats too. And you never know when someone will need help.
So for me it was economy, reliability