: There are plastic waterproof zippers that have been used in some dry suits
: and are often used in deck bags. They're much cheaper than the brass
: zippers, but they have a less than stellar reputation when it comes to
: strength. I don't know if I would risk using one on a kayak unless it was
: a secondary closure (like a storm flap) that wasn't under lateral tension.

My deck skins aren't under much lateral tension, so that might work. I found
something similar from Seattle fabrics, but they are too short and are non-
separating. Who makes / sells the ones you are describing ? I bought a #10
marine grade plastic non-waterproof zipper that I'm going to test first.
Steve's suggestion below may be just the ticket.

: Would using lacing to close/tension the skin and a zippered flap to cover the
: lacing be a viable idea?

I've used lacing before on a couple of kayaks. ( See Pic) Grommets are way
too slow to lace, and the homemade aluminum speed laces I made were fast
enough, but over time, protruded into the Velcro flap making for a lumpy look.
Actually, a 2" Velcro flap alone is more than adequate to close a deck as little
tension is actually generated. It's pretty watertight, in all but the most
severe conditions (rolling).

Thanks for your input.

Tom