Electric Propulsion Device for Surfboard with Flexible Shaft Drive

An electric propulsion device for a surfboard comprising:

• a watertight electronics compartment configured to be embedded within a cavity in a surfboard;
• a motor compartment, separate from the watertight electronics compartment, configured to be exposed to water, the motor compartment having an external surface with a plurality of holes formed therethrough;
• an electric motor disposed within the motor compartment;
• at least one battery and an electronic speed controller disposed within the watertight electronics compartment and operatively connected to the electric motor;
• a fin assembly attachable to the external surface of the motor compartment, the fin assembly comprising a propeller;
• and
• a flexible drive shaft having a first end operatively connected to the electric motor and a second end operatively connected to the propeller, the flexible drive shaft being configured to transmit rotational power from the motor to the propeller.