The floating batteries would have strong, thick wooden armour— timbers packed with layers of wet sand, with water pumped over them to avoid fire breaking out. In addition old cables would also deaden the fall of British shot and, as ballast, would counterbalance the guns' weight. Guns were to be fired from one side only; the starboard battery was removed completely and the port battery heavily augmented with timber and sand infill. The ten floating batteries would be supported by ships of the line and bomb ships, which would try to draw away and split up the British fire. Five batteries each with two rows of guns, together with five smaller batteries each with a single row, would provide a total of 150 guns. The Spanish enthusiastically received the proposal. D'Arçon sailed close to shore under enemy fire in a skiff to get more accurate intelligence.
