Larry; I'm planning on installing a fairly simple single davit on my Titan. It will be used to lower and lift a mobility impaired (the Captain) in and out of the water/dingy. I was planning on a single boom of 1 1/2" stainless that swivels on a base mounted thru the side deck adjacent to the exit thru the rails. Long enough arm section to swing clear of the hull, and back over into the cockpit area.
It will mount on a tube base with nylon sleeves, and have a remote controlled winch for raising and lowering the seat (not figured out yet, but probably a plastic, ie cheap kitchen chair, mounted on stainless frame.)
If this is of any help, I can possibly do up a sketch and try to download it ( computer literacy isn't my strong skill)