CAPE ELIZABETH – An explosion blew a lobsterman off the stern of his boat, but he managed to swim to safety after his vessel caught fire and sank six miles off Cape Elizabeth.

According to the Coast Guard, Kenneth Johnson was pulling traps by himself Saturday morning when he made an emergency radio call reporting an electrical fire.

Coast Guard search-and-rescue specialist Kenneth Stuart said after Johnson got his survival suit on, an explosion blew him off a rear platform of the 45-foot Kimberly Marie.

A sport fishing boat retrieved Johnson from the water, and he was taken to Portland and to Maine Medical Center with rib injuries.

The boat, whose home port is Cundy’s Harbor, later sank. Smoke from the fire was so thick that the Coast Guard got calls about the fire from Saco to Harpswell.