I would like to install a windlass on my one-year old PSC31. It seems the chain locker is not deep enough to allow a vertical windlass to work properly. So a horizontal one is recommended.
We own a PSC 31, but it's not equipped with a windlass. However, I have never heard of a clearance problem such as you describe above. My suggestion would be to join SailNet's PSC e-mail list serve ( http://list.sailnet.net/read/?forum=pacificseacraft ) and post your question there. There are quite a few 31 owners on the list and many of them have windlasses, so hopefully you could find an answer. Good luck to you.