 On 6 May the conditions for Muskein 's attack were perfect : the calm winds prevented the British warships intercepting his flotilla , and the weak tides prevented disruption to his craft by heavy waves . The British also were aware of the conditions necessary for the attack , and made swift preparations to arm the batteries and line the shore with Royal Marines . A small boat from the islands watched as Muskein 's force rowed out of Saint @-@ Vaast @-@ la @-@ Hougue and steadily approached the islands during the evening . The sixth rate HMS Eurydice under Captain John Talbot and the brig HMS Orestes under Commander William Haggitt , had joined Adamant , which was stranded 6 nautical miles ( 11 km ) away from the islands by the calm . Despite strenuous efforts , the three vessels would not be able to reach the islands in time to take part in the action . 
