As it was apprehended, that the enemy's ships might come too near the town, and annoy the rear of the British lines, Captain Moncrieffe had some fire-rafts prepared, and in readiness to act against them, if they should make the attempt. It was also judged expedient, in order effectually to prevent it, to sink a number of vessels to stop up the passage. As his Majesty's ship the Rose was in so very bad a condition, that, by the report of shipwrights lately employed to survey her, she could not swim above two months; as her guns, ammunition, and stores, had been landed; and as her weight would keep her across the channel, when lighter vessels might shift, owing to the rapidity of the current, and to the hardness of its sandy bottom, in which they could have little hold, Captain Henry selected her as a vessel proper to be sunk. The Savannah armed ship, and four transports, were also scuttled and sunk, and by these the channel was blocked up. Above the town several smaller vessels were sunk, and a boom was laid across the river, to prevent the enemy from sending down fire-rafts among the shipping, or landing troops in the British rear. Previous to the vessels being sunk, the Fowey, Keppel brig, Comet galley, and Germain provincial armed ship, were got up to the town: and the latter having guns, was placed off Yamairaw, to flank the lines. While the enemy's batteries were getting ready to play against the town, three French frigates advanced up the river to Mud-flat. One of them, having twelve-pounders, and two rebel galleys, carrying each two eighteen-pounders in their prows, anchored in Five Fathom Hole; from which one of the frigates sailed into the back river, with a design to cannonade the rear of the British lines. She fired a great number of shot; which, being at their utmost range, did no execution. The galleys advancing nearer, did some damage to the houses; but a few shot now and then from the river battery, made them keep a respectable distance. Two sallies, one of them on the 24th; commanded by Major Graham, of the 16th regiment; and another on the 27th, commanded by Major M'Arthur, of the 71st regiment; were admirably well conducted, did the enemy considerable mischief, and killed and wounded a great many of their best troops, while the loss on our side was very inconsiderable; In the first sally, Major Graham artfully drew the enemy into a snare, by which the French and the rebels fired on each other, and had near 50 men killed before the mistake was discovered.