Re-using Equipment for Environmental Fortification Act of 2023 or the REEF Act of 2023 This bill requires the Department of the Navy to notify Congress when a vessel that is a viable candidate for artificial reefing (intentionally sinking a vessel to promote marine life) is to be stricken from the Naval Vessel Register. Specifically, the Navy must provide such notice not later than 90 days before the viable candidate is to be stricken from the register.