The plan began the next evening. In the clearness of the summer Canary night, citizens realised that blurry figures were sailing towards the pier: the British boats, carrying the troops, were on their way. They were in two groups: one of 23 boats and launches heading for the Bufadero cliff; the other, 16, coming right into the city. Authorities were updated as adverse currents held the British back. No marine bombardment was likely as ships could not get any closer and even though frigates could, the frigates' naval guns could not be elevated sufficiently for their shot to reach the city. The British had just one mortar which, however, could inflict little damage. They had no howitzers, and carronades too were of no use in this situation. Spanish cannons began firing heavily on the boats, wrecking some of them. The currents were too strong and the British decided to go back to the ships.