Early on the morning of April 19, Elbert took the galleys down the river to attack the British ships, which were already ranged in their order of battle. The galleys likely initiated the attack shortly after first light, around 5:30 that morning, beginning their assault on the Hinchinbrook, Rebecca, and Hatter. Galleys are lightly-built craft that are optimized for rowing. They are fragile and at a severe disadvantage against strongly-built sailing vessels. However, galleys have a tactical advantage against pure sailing vessels in restricted waters or when there is no wind. Either by happenstance or by brilliant planning, the ebb tide combined with the lack of wind to give the Americans the advantage; with no wind, the British ships were unable to sail forward to board and storm the galleys, and were forced to remain stationary. Consequently, the galleys began by firing a few random shots at the British vessels before anchoring a safe distance away and beginning a heavy cannonade.
Hinchinbrook and Rebecca carried four-pounders which were no match for the heavier ordinance on the galleys, so they began dropping downriver, hoping to find a place to maneuver and possibly catch a breeze. They thought that the channel was deep, and sailed accordingly; however, at around 10 in the morning, Rebecca suddenly became grounded at a place called "Raccoon Gut". Hinchinbrook and Hatter soon suffered the same fate. As the galleys were drawing nearer, the British made the decision to abandon ship. Most of the officers and men crowded into the ship's boats and rowed downriver to Galatea, which was still anchored in the Sound. A few of Hinchinbrook's crew were left behind.