Join Date: Aug 2009
Thanked 0 Times in 0 Posts
Rep Power: 0
Outboard, how long a shaft does it need to be?
I have a Cal 24 (Hunt) that I just traded another boat for, and it came equipped with a 6hp Mercury outboard that runs very well. It is, however, a short shaft model which I at first thought adequate, but now wonder if I really need a long shaft model. The day I got the boat I brought it across the Bay from St. Michaels to Deale and it functioned perfectly, but that was a windless day and the water was flat.
Last weekend I finally took her out for a sail, and in about a foot of chop it seemed to me the prop was surfacing more than it should. I looked at guidelines for determining prop shaft length, but I guess those are primarily for powerboats. On my boat the outboard is mounted on one of those fancy mounts that go up and down (Garelick I believe) and it places the cavitation plate several inches below the surface, but now that doesn't seem deep enough. Of course I think that mount also moves the motor back another foot from the transom, so that doesn't help.
I suppose I'm answering my own question--if I'm worried about it I need a longer shaft--but wanted to get more knowledgeable opinions. I've had outboards before, but they were mounted in wells that kept them down more reliably, AND they were long shafts (even on a Kittiwake, which is spec'ed for a short). I suppose I was looking for a more sailboat oriented guideline for how deep it should be?
(BTW I did do a search for this, but there's a LOT of discussion on outboards and I honestly didn't wade through the entire list of results.)