Access opening seal for attachment to the lip of an access opening having an exposed edge, particularly an access opening of a personal watercraft. The seal includes a top portion and a side portion and may further include a bottom portion with the side portion being between the top and bottom portions. The seal portions cooperate to define an interior surface and exterior surfaces. The seal may be affixed to the lip of an access opening with the interior surface of the top portion abutting the outer wall of a personal watercraft top deck or other structure and with the side portion positioned along and covering the exposed edge. Where a bottom portion is provided, the bottom portion abuts the inner wall of the top deck or other structure. The seal may be formed of a polymeric or other material and cooperates with a storage compartment and/or cover to form a watertight seal. The seal may be affixed to the lip of the access opening, with an adhesive or mechanical fastener.