Avoid anything with a strap and buckle (eg. Chinook in-flight), the strap salts up and becomes so stiff that it won't adjust.
Avoid anything with moving parts (eg. North vario), salt and sand get in there to stop things working.
About the only thing we're left with are V-jam cleats, the Dakine set I bought were useless because the sewing for the boom attachment was way too close to the edge, ripping out after just one month, making me buy some webbing to make some new attachments.
So that leaves
Flying ObjectsSailworks (Edit: it was dark in the shed

), which I'm quite happy with, I'll be buying more when my current set give up:
http://www.boardcrazy.ashop.com.au/p/382902/sailworks-adjustable-harness-lines.htmlAs for outhaul, never had any problems with my chinook setup, my cleat doesn't corrode at all, doesn't move once I put some plumbers tape underneath the plastic clamps, and works a treat.