An explosion aboard a ship has forced the bulk carrier Sea Moon to make an emergency medical stop at the Island.A crew member was knocked overboard, and hatches damaged, when the vessel was about 120m southwest of Bermuda.According to a Bermuda Maritime Operations spokesman, the vessel will stop to ascertain damage, and have the injured crew member brought ashore.East End residents may spot the unusual caller at anchor this morning. The vessel was expected to arrive at 2am.Added the spokesman: “Coal can be a quite volatile cargo, either from gas or dust. Right now we don’t know the exact details.”The ship was en route from New Orleans to Karachi, Pakistan.