If you don’t use the sensor plug, you can basically submerge them and they’ll still operate.
It will drastically reduce bearing lifetime though, especially if the water has salts in it. Motor bearings are replaceable though in all but one kind of motor I have dealt with.
The sensors are a completely different story and I just recommend not using them unless you absolutely have to. I wouldn’t get them wet unless you personally seal them up inside the motor. SOME motors have this already done, like the new Bioboards motors, but not very many.