A US Coast Guard crew based in Boothbay Harbor, Maine, witnessed a shark swimming alongside the bow of their boat as they returned from a search and rescue mission on July 3.The crew were around eight miles out to see when the shark swam below the 47-foot lifeboat, the coast guard said.Speaking to local media, Chief Adam Smart said the measurement was not an official one. There were 10 crew members aboard and those who responded used the length of the boat as a base for their approximation. Credit: US Coast Guard Station Boothbay Harbor via Storyful