Propulsion drive assembly with gas supply to mitigate fouling

A propulsion drive assembly for a marine vessel, said propulsion drive assembly comprising:

• a propeller drive unit for carrying and driving at least one propeller,
• a housing for connection to a hull of the marine vessel on an inside of the hull such that the housing surrounds a first opening of the hull and seals to the hull, wherein the housing defines an inner space and wherein the housing is provided with a second opening through which the at least a portion of the propeller drive unit is movable into and out of the inner space through the first opening,
• a suspension mechanism attached to the housing and configured to suspend the propeller drive unit, wherein the suspension mechanism is movable along a first longitudinal axis of the housing between a stowed position, in which the propeller drive unit is positioned inside the inner space of the housing, and a deployed position in which at least a portion of the propeller drive unit protrudes outside the housing through the first opening, and
• a gas supply device configured to supply gas into the inner space of the housing, said gas supply device comprising a gas pump or a controllable valve connectable to a source of pressurized gas.