While the main fleets manoeuvered Hold around one another , `` Castor '' was detached in pursuit of a Dutch merchant ship and on 29 May encountered Hostile_encounter the smaller independently cruising British frigate HMS `` Carysfort '' .

Captain Francis Laforey on `` Carysfort '' immediately attacked Attack the larger ship and in an engagement lasting an hour and fifteen minutes successfully forced its captain to surrender Surrendering , discovering Know a number of British prisoners of war below decks .