Yes, it's their 207 resin - but there are two problems involved in using it. First of all, it (like any resin) does not go on smooth like varnish. You would need to add about three coats and then sand it down smooth to get a presentable looking surface. Secondly, it still needs to be varnished-over with a good UV filtering varnish in order to protect it from UV damage. Bare epoxy resin has a rather short UV lifespan before it breaks down. This is WEST Epoxy in it's natural hardened state, followed by how it looks after being sanded smooth, varnished and the varnish sanded smooth and polished:
In order to get a water clear varnish, you pretty much have to lose the linseed oil base and go to a water-based product. These tend to vary a lot in terms of water resistance. The one I use is Enduro Pre-Cat, water-based one-part conversion varnish, which is great stuff, but needs to be sprayed.
https://generalfinishes.com/sites/default/files/file_downloads/Tech-Data-Pre-Cat-Urethane-060310.pdf
The water-based varnishes are all pretty thin (many about like milk). It might take quite a few coats to get what appears to be a nice, deep finish. Those made for wood floors (Minwax, Flecto Varathane Diamond, etc.) are brushable, but still pretty thin compared to oil varnish and they don't flow the way oil does. Some will withstand a day of paddling immersion, others may not.
There is a clear grade of shellac that is supposed to be a lot less golden in color than varnish. I have always used the amber stuff and can't say anything about the clear version, but it might be worth investigating.
Best option? It may well be to plan for some yellowing when picking your colors, make the most of the antique look it can provide and stick with good old spar varnish.