Have you tried the Kickboat in the salt? I love mine and use it a fair bit out of Capitola (South of Santa Cruz). I launch off a floating dock mostly but have gone through the surf a few times. I haven't tried launching in anything over 3 or so feet but have recovered in 6+feet. I figure I look a lot less like a seal in my Kickboat than when I was using a U-tube and I'm not on the bulls-eye anymore either. I wash it every time with salt-X and haven't had any problems. I pull the foot-pegs out and squirt it up into the frame pieces.
Tight lines,
Wade