Eli5: How does water not get inside ships or submarines through the motor shaft?

Question

Eli5: How does water not get inside ships or submarines through the motor shaft?

In: 112

Answer 1

Not just the prop shaft but water enters large ships everywhere. They get gathered in a sump at the bilge. And it gets pumped out regularly from there.

In a large ship,even with a 100% watertight hull, rainwater or sea spray will slowly enter the ship one way or another and these collect at the bottom eventually to be pumped out.