San Luis Pass is a strait of water at the south-western end of Galveston Island off the Texas Gulf Coast of the U.S. state of Texas. It connects the sheltered waters of West Bay to the open Gulf of Mexico. Fishermen and swimmers have been killed in the Pass' treacherous waters, largely due to the aggressive oceanic currents of Gulf Stream, fluctuating tides in marginal sea, marine sediment, and uncertainties of continental margin. The San Luis Pass-Vacek Toll Bridge spans San Luis Pass from Galveston County to Brazoria County.