boat shaft grease
Go to your local Wal Mart and get you some waterproof wheel bearing grease in a tube, thats what I use on all my prop shafts. Its a Bright "Baby Blue" color and believe me it works, I use it on the wheel bearings on all of my boat trailers, and when I repack the wheel bearings on my vehicles. In the last 10 years Ive been using this stuff, Ive yet to have a bearing failure. If you cant find it at Wal Mart try a boating center or dealer.