[4] It proved to be a difficult task due to the large number of inlets, keys and natural ports of that coasts that allowed the much inferior Spanish vessels to break the blockade many times.

The naval units based there were the gunboats Alerta, Ligera and Antonio López, the last a former tugboat operated by the Spanish Line, which had ceded it to the navy.

The entrances to the bay were covered by 20 Bustamante mines, most of them defective, and a 70-men company of marines had been detached to garrison the town.

[1] The gunboats belonged to the Spanish Caribbean squadron under Admiral Vicente Manterola, and most of its units had been described as "unhelpful even to the coastal police".

Her commander was Lieutenant Antonio Pérez Rendón y Sánchez, an experienced Cádiz-born officer who had seen action against the Cuban insurgents many times during the war.

[8] Saranac, under Captain Bartaby, was carrying 1,640 tons of coal from Newcastle, New South Wales, to Iloilo, for Admiral Dewey's fleet.