Final San Antonio Keel. The Navy and shipbuilder Huntington Ingalls Industries have authenticated the keel of the future USS Portland (LPD-27), which is slated to be the last of the San Antonio-class (LPD-17) amphibious transport dock ships the Navy plans to build for Marine Corps operations. The keel laying took place Friday at HII’s shipyard in Pascagoula, Miss. The Portland will be the 11th San Antonio-class ship. “This keel laying is especially important as the final ship of the current San Antonio class,” says Capt. Darren Plath, LPD-17 class program manager at Naval Sea Systems Command (NAVSEA).