Constant submersion gear boxes?

[Pylasteki]

Hi guys,

I'm building a bow thruster, and I'm wondering about the type seals and bearings used on these things?

The bearings I'm having a hard time with as they are helical spur gears, keep wondering if each shaft could have one taper bearing and one ball bearing, and just use the helical gear to take the thrust in one direction.

That and I don't have a cutter that will reach deep enough to cut a shoulder at the bottom of the bore to hold another taper bearing. I do however have a boring bar that I'm thinking will work so long as the ball bearing is pressed against a shoulder on the shaft.

Thanks guys... This thing is keeping me up at night, and I've got timken numbers coming out my ears.

Zach