The British fleet was composed of nine man @-@ of @-@ war ships : the flagship 50 @-@ gun Bristol , as well as the 50 @-@ gun Experiment and frigates Actaeon , Active , Solebay , Siren , Sphinx , Friendship and the bomb vessel Thunder , in total mounting nearly 300 cannon . The army forces in the expedition consisted of the 15th , 28th , 33rd , 37th , 54th , and 57th Regiments of Foot , and part of the 46th . On June 7 , Clinton issued a proclamation calling on the rebel colonists to lay down their arms . However , the inexperienced defenders fired on the boat sent to deliver it ( which was flying a truce flag ) , and it was not delivered until the next day . That same day , Clinton began landing 2 @,@ 200 troops on Long Island . The intent was that these troops would wade across the channel ( now known as Breach Inlet ) between Long and Sullivan 's , which the British believed to be sufficiently shallow to do so , while the fleet bombarded Fort Sullivan .