Abstract: Disclosed is a passively cooled waterproof propulsion unit for a watercraft is provided comprising a substantially cylindrical housing including an outer wall having an external surface and an internal surface. The cylindrical housing includes a first end cap attached at a first end of the housing. The first end cap includes an attachment interface configured to be mounted to a strut of a watercraft such that at least a portion of the external surface of the outer wall of the housing is configured to contact a fluid surrounding the housing when the watercraft operates within the fluid. The propulsion unit further includes an electric motor disposed with in the housing and an electronic speed controller. The electronic speed controller is electrically coupled to the electric motor and configured to provide electrical power to the electric motor to operate the electric motor.

Abstract: A self-contained battery assembly is provided that is configured to be removably coupled to a watercraft. The battery assembly comprises a waterproof housing including a top portion and a bottom portion that houses a plurality of battery modules. The battery assembly includes a plurality of battery separators manufactured from a material to provide passive protection against thermal event propagation and an electronics module. Each of the battery modules is surrounded on four sides by the one or more of the plurality of battery separators. The plurality of battery separators are disposed within the housing and in physical contact with the top portion and the bottom portion.