I'm refinishing a North Bay kayak for someone who wants a satin finish.

I like the look of a satin finish also, but my standard caveat is that part of the UV protection of varnish comes from it being glossy and reflective. Some of the UV is reflected by the gloss, and that means less UV penetrates the varnish, thus more UV protection. This may explain why most satin varnishes are not recommended for exterior use.

This loss of protection is probably not a big deal for a kayak stored inside, in a northern climate, and when the boat has regular maintenance, but it is one thing to consider when making a decision.

Given that, I will add one more option for achieving the look. I have applied multiple coats of standard gloss varnish and then for the last coat after a fine sanding I sprayed the whole thing using a couple rattle cans of spray satin. I told the customer the tradeoffs and he still wanted the satin look, and it did look nice.