46 CFR § 111.101-3 - General requirements.
(a) Each electric motor driving a submersible bilge pump must be in an open end air bell of rugged construction and be of a size that does not allow water to enter the motor if the compartment that the motor is in is flooded to the uppermost continuous deck.
(b) The motor, if of the open type, must be protected from splashing water from the bottom.
(c) The cable to each motor must enter through the open bottom of the air bell.
(d) Each motor must be able to operate continuously at rated load under any condition, dry or with water in the air bell at any level up to the maximum allowed under paragraph (a) of this section.
(e) Each motor controller must be above the uppermost continuous deck. There must be a master switch at the controller and a master switch at the motor. The master switch at the motor must be disconnected from the circuit when the motor is started or stopped from the master switch at the controller.
(f) Each motor must be energized from the final emergency power source.