I've got a shaft that rotates at about 1 rpm and handles a radial load of approximately 25 lbs, a thrust load of 17 lbs, and a bending moment of about 150 lb-in. The shaft and joint will be submerged in lakewater. A shaft diameter of 1.5 in would be nice, but in general a larger shaft would be preferable to a smaller one. I was looking at bushing options, but I'm starting to wonder if I need a bushing of any kind at all (considering the low loads and very low rpm). It seems that a no-bushing solution would also go hand in hand with a larger shaft diameter.