Following the air strikes on airfields on April 15, 1961, the FAR managed to prepare for armed action at least four T-33s, four Sea Furies and five or six B-26s. All three types could be armed with machine guns and rockets for air-to-air combat and for strafing of ships and ground forces. CIA planners had reportedly failed to discover that the US-supplied T-33 jets had long been armed with M-3 machine guns. The Sea Furies and B-26s could also carry bombs, for attacks against ships and tanks.
No additional air strikes against Cuban airfields and aircraft were specifically planned before 17 April, but pilots' exaggerated claims gave the CIA false confidence in the success of the 15 April attacks, until U-2 reconnaissance photos on 16 April showed otherwise. Late on 16 April, President Kennedy ordered cancellation of further airfield strikes planned for dawn on 17 April, to attempt plausible deniability of US direct involvement.
On April 16, Merardo Leon, Jose Leon, and 14 others staged armed rising at Las Delicias Estate in Las Villas, only four survived Leonel Martinez and 12 others took to the countryside (ibid). On April 17, 1961, Osvaldo Ramírez (then chief of the rural resistance to Castro) was captured in Aromas de Velázquez and immediately executed. The CIA was unaware or unconcerned at this repression's effects on the planned operation (notably two former "Comandantes" Humberto Sorí Marin and William Alexander Morgan). Others executed included Alberto Tapia Ruano, a Catholic youth leader. Some estimates quote several hundred thousand people as being imprisoned before, during, and after the invasion.
Late on April 16, 1961, the CIA/Brigade 2506 invasion fleet converged on "Rendezvous Point Zulu", about 65 km (40 miles) south of Cuba, having sailed from Puerto Cabezas, Nicaragua where they had been loaded with troops and other materiel, after loading arms and supplies at New Orleans. The fleet, cryptically labelled the "Cuban Expeditionary Fo...