Jamie Boeckel, 31, of Newport, R.I., boat captain of the 66-foot ocean racing sloop Blue Yankee, was swept overboard on May 24 in Long Island Sound and is presumed dead. The incident occured during the Storm Trysail Club's Block Island Race. Boeckel was thrown from the bow when the spinnaker pole broke off Fairfield, Conn., while the 16-man crew was making a routine sail change to a smaller running spinnaker. It was 8:37 p.m. and just after dark. At the time, northwesterly winds were gusting over 25 knots following the passage of a cold front.