The best epoxy will depend on the depth of the river table. TotalBoat ThickSet Cast + Coat Deep Pour Epoxy Resin can be applied up to 1/2 inch deep per layer, or up to 2 inches deep if no more than 10 ounces of epoxy will be used. TotalBoat Fathom Deep Pour Epoxy Resin can be applied up to 2 inches deep per layer, or up to 3 inches deep if no more than 1 gallon of epoxy will be used. Fathom should not be applied in layers thinner than 1 inch.