HOME SWEET SANDBAR: ‘How the Waves Were Won’ isn’t just any lifeguard movie; it’s a documentary about Long Beach Island’s very own lifeguards, specifically the Harvey Cedars Beach Patrol and its quest to win a seventh Long Beach Island Lifeguard Championship last summer. The 35-minute film, directed by Michael Furno, had its world premiere at the Lighthouse International Film Festival Sunday afternoon at the Long Beach Island Foundation of the Arts and Sciences.