The Coast Guard rescued three crew members from a fishing vessel that caught fire and sank off Cape Cod Tuesday. There were no injuries reported after the 48-foot Joanne H went down about 17 miles east of Chatham. The Coast Guard received an emergency call from the Harwich-based vessel about 5:45 a.m., but lost contact before the boat’s position was transmitted. Using a satellite monitoring system, a helicopter and cutter went to the boat’s last known position and found the Joanne H fully engulfed. The crew, in a life raft, fired a flare to alert the Coast Guard to their position. The boat sank in about 300 feet of water and is not considered a navigational hazard.