The aquamarine waters and golden sands of Fort Pierce, Florida, are a fitting setting for the National Navy UDT-SEAL Museum, which bills itself as “the birthplace of the Navy Frogman.” After all, it was here on the state’s mid-Atlantic coast, locally referred to as the Treasure Coast, that the frogmen were first trained during World War II. The museum tells the story of the SEALs and the American naval special-warfare units that preceded them.