Not only have we had the prop come out of the water but we have also dunked the powerhead under it. I guess the cowling protects from water getting into the electronics and holds enough enough air to keep the engine running for a few seconds. Our 10HP 2 stroke Nissan kept on tiking. Conditions; sailing our Starwind 223 into Mystic, Connecticut they day after a storm when boats twice our size were afraid to leave port. Wind 25-30 knots and waves hard to judge but minimum 7 feet. Following seas have had no effect on our trusty Nissan