sentences:  During November 1951, she was forced to leave Ocean Station Alfa for a short while due to an urgent medical case.On 19 February 1952, "Dexter" left Ocean Station Hotel to assist the merchant ship SS "Helen Stevenson", which had cracked across the main deck port and starboard at the hatch.She escorted "Helen Stevenson" to a point less than 10 nautical miles (18.5 kilometers) east of St. George's, Bermuda, and then returned to station.