This is may favorite marine duct tape. It's a UV stabilized, white in color, heavy duty duct tape made by Duck brand. It is hard to find but I have found no better duct tape, in white, that is also UV stable for use on a boat.

I use this tape to seal off the underside of the deck. This prevents the epoxy from dripping into the cabin. Gorilla Tape is even better for this as it is even more adhesive! Unfortunately Gorilla Tape only comes in black.