Taped seam construction can't be done without epoxy and fabric reinforcement at the seams and joints. Polymers by their nature aren't the nicest things in the world to work with in an uncured state. Epoxy is pretty nasty stuff if you eat, drink, permit abortion into skin, lungs, rub it into eyes, etc. With reasonable care (gloves and protective clothing) you can work in open environments or up wind with great safety. Protective masks when sanding hardened epoxy will save your lungs.
All the manufactures provide a "hazardous materials" as well as a "physical properties" .PDF on line so you can compare the different brands.
Every once and a while we'll hear about a novice, turned amateur chemist/materials engineer, trying to tape their seams with drywall tape and some other "stick-um", but I've never seen any of these home brewed techniques work.
There are no single part epoxies available for the marine environment.