Chaps. I have never bothered to filled my shafts with anything and just get by on an iniatial grease-up on first assembly, then a drop if 20/50 now and then on the bearings. Dont like the idea of oil filled shafts, as when water gets in it will emulsify and trap water on the shaft, and to my mind if water is getting in, oil must also be getting out into the pond. I dont seem to have much of a problem with water ingres, I keep my shaft nuts well adjusted so there is the absolute minimum play end-to-end and find , along with a blob of grease (i like coppaslip) that this is sufficient. You can buy waterproof greases, as used on car waterpumps but I suspect that unless your boat is out in the oggie every day this would make little differance. Ashley