One man has died off the coast of Portsmouth after the boat he was in capsized.  The AP reports the 65 year old man was in a boat with one other person about 100 feet off shore Thursday afternoon when it over turned.  Chief Michael O'Brien of the Porstmouth Fire Department told WPRI-TV that several people who witnessed the accident attempted to help.  The man was unresponsive when he was brought out of the water and a bystander performed CPR on him.  He was brought to St. Anne's hospital, but died.  No names have been released at this time.