I would say tons of boaters use electrical tape as grip/marking tape. With that being said I wrap my paddle with self tacky gauze tape for tennis rackets. It is mostly water proof, and will last about a month for pretty heavy boating, around two weeks for everyday boating. It will last longer, but I like it pretty fresh so I reapply a ton. I use a whole roll for the first application, and then you can get away with removing the first few layers, and reapply those to save tape. At the end of the season I cut it off, and start over. (if you hand paddle the tape will last much longer
I am attaching a link of the best tape to use it is cheap, and wide so it covers a large area. I have been using this since I started, and a friend showed it to me. It sucks because now when I use a paddle with out it I think it is to slippery.
Here is a link to what I am talking about.
Gamma Gauze Tape Blue 30 ft Roll - Agt-10 - Tennis Overgrips Grips