The YO-257, a 175-foot long navy oiler, sits on the sand in 100-feet of water off the south shore of Oahu. You’ll have a breathtaking view of Diamond Head on your boat ride to this wreck. It was purposely sunk in 1989 to form an artificial reef by Atlantis Submarines and has since been teaming with marine life. Large turtles like to lay on the main deck at 75 feet and schools of spotted eagle rays cruise past the ship on both sides. Swim throughs are abundant here.