I also am curious about your use of "white graphite" or boron nitride as a bottom finish.

I used it on a couple of kayaks when it seemed to be a fad on this board. I never had good luck with it. It was tough to get a smooth surface and what I did get was impossible to keep clean. It ended up getting a brown tinge to it from fresh water fouling. One customer has his Njord recoated with Interlux VC Performance Epoxy and has been very happy.

I wonder if you tried the airboat coating and if so, how you feel about it?

To date I've only tried their Speedcoat-49. It's similar to the Wearlander but made for high speed craft.

I've used it on a couple of race hulls and also on the bottom of my Black Pearl. It's very thin and very slick. Even sprayed it has a slightly dimpled surface, by design. It has helped with abrasion but has limitations: seeing there is silicone in the matrix you can never coat it with anything else but itself. It's VERY slippery. It makes the kayak tricky to handle and the boat can slide around in cradles. I only put it on the wetted bottom and stems for those reasons.

Wetlander is applied thicker and should be more rugged. I have a quart of it in the shop in graphite waiting for a project.