Sensors are for pussies!
I'm guessing the fan & housing unit on top of the esc are designed to be easily removable with a small flat bladed screw driver- nice bit of design. I wonder though, how many people will be moaning about dead fans because they didn't remove them, and I wonder how many people will complain of dead escs when they ran them fully submerged for long durations ( disclaimers are great when people read them )...