When the USS Bancroft fires warning shots on Mendoza's yacht, the explosion is seen on the port side of the Tropical Pleasure. Later, when the Chief Petty Officer dives to the yacht, she indicates that the hole is on the starboard side.
The footage used for the USS Bancroft is that of the Spanish frigate SPS Victoria (F82), which is a Santa Maria class frigate based on the American Oliver Hazard Perry class design, and has no 5 inch gun and no forward gun. In the opening scene the commanding officer of the USS Bancroft orders one shot across the bow from the forward gun. The footage that's then shown is that of a 5 inch gun on the forecastle.