A propulsion system, for use by a swimmer in both on-water and underwater applications, includes at least one power supply unit attachable about a sleeve secured about a forearm of the swimmer, at least one corresponding propulsion unit including a motor and an impeller, the motor in electrical communication with the motor controller, the propulsion unit within a housing, the unit extending in a direction laterally offset from the forearm, near to the wrist and away from the head of the swimmer; and control apparatus for the power and propulsion units. The control apparatus includes elements for controlling pitch of an axis of the propulsion unit relative to a forearm of the swimmer, the control elements including a pivotally secured bracket, and elements for control of the level of power provided to the propulsion unit, in which each of the rotating and control apparatus are positioned for ease of accessibility by a hand of the swimmer.