A snap cover converter couples a boat cover to a boat. The converter has a snap portion that snaps to a mating snap portion on the cover, and will remain snapped thereto until a person removes the snap cover converter. A loop, when secured, extends from the snap portion snapped to the cover to and about either one of a male snap member affixed to a boat, or a knob that may be used in addition to or to replace a prior art snap member. The knob has a top, a base, and a shoulder intermediate between top and base that together engage securely with an opening in the loop. In one preferred embodiment, the loop opening is keyhole shaped, and the knob top has a generally cylindrical exterior of a diameter greater than the knob shoulder and less than a diameter of the knob base.