For SplashZone, you probably need to go to the fishboat chandelry...I don't think it's "yachty" enough for Westwhatever.

SplashZone is a two-can, two-part, strongly foul smelling underwater cure epoxy product. Industrial Marine-Tex, as it were. Have to mix the two parts (black and bile green) together in roughly equal amounts as needed ---and you have to keep the lump wet! Hands, too! Turns more-or-less OD Green when you have it mixed right. Really good for sculpting and so on like you had to do around your cockpit drain pipes.

Since it has to be wet, it dribbles this OD green juice everywhere...that does a dandy job of permanently staining any porous surface...like paint or gelcoat. It is tough stuff. Not sure it's going to do what you just clarified, though...it IS really handy for a lot of other uses, you ought to give it a try. Thick, tough putty in whatever quantity you feel like mixing...pretty neat.

Being ever the low-tech, non-esoteric cheapskate that I am I have found pretty good success at hull fairing with epoxy resin and balloons(for sandability) with 1/4" milled glass fiber added for strength...to my experience, it sands a lot better than if you put silica in it, and I haven't had any crack or fall off anything I've put it on over the course of quite a few jobs and about a 15 year span. I did it out of frustration once because the silica-filled stuff...well, you know...I was ending up with silica-filled humps surrounded by low spots. I really like to use a DA for that kind of work anymore if there is air to be had, though...cuts faster than an electric RO and has a lot more control...and I am a big fan (itchiness aside) of mill fiber for "structural" fillers, mainly because it's cheap and tough. While I'm sure there is a better mousetrap made, I tend to go with the more-or-less "old school" goods an awful lot as long as I know they do the job adequately...saves a lot of $$$. I'm preaching to the choir...I better just shut up and let ya sing!

Dave