I guess it depends on your definition of water resistance. I wouldn't choose it for a marine environment, but as a stock finish it is better at sealing out moisture than BLO when used alone.
I agree that Tung oil is better than BLO in humid environments. That's why the US military made the switch to Tung in 1942. It provides better rot resistance when subjected to high humidity environments, and maybe water proof would have been a better term since neither of them are actually a barrier to water when applied to a rifle stock in the traditional manner. The non-darkening advantage is true but strictly cosmetic, IMO. There is no doubt that overall Tung oil is superior to BLO. I have no knowledge of its use in the boating world.
Just for those that may not know better, I'm speaking of real Tung oil, made from the nut of the Tung tree and not that Formsby "Tung Oil Finish" stuff. Formsby TOF is ok as a furniture finish but it isn't the same as true Tung oil and is more like a thin varnish.
As far as I know waxy shellac actually has superior moisture resistance to the de-waxed variety. Again, as far as I know, the main advatange to the de-waxed shellacs is if you are using it as a seal coat or primer for the application of a non-shellac top coat. Which brings up another excellent use of shellac, it is very good at sealing knots and such when painting pine. Use a seal coat of de-waxed shellac before painting and the knots won't bleed through later. It's probably the best product I've found for use as a sealing primer.
In any event I use my "gunny paste" as a finishing touch on most all of my rifles with traditional finishes.