| Lead Boat: SS-212, U.S.S. Gato |
| Length: 312' |
| Beam: 27' |
| Draft: 17' (Surface trim) |
| Displacement: 1,800 tons (surfaced); 2,400 tons (submerged) |
| Speed: 20-1/4 knots (surfaced); 8-3/4 knots (submerged) |
| Diving Depth: 300' (test depth); 450' (emergency) |
| Range: 20,000 miles |
| Endurance: 75 days |
| Crew: 6-10 (officers); 60-70 (enlisted) Crew size increased as war progressed. |
| Deck Gun: 1 3"/50-calibre, or 1 4"/50-calibre, or 1 5"/25-calibre |
| Anti-Aircraft Weapons: 1 or 2-20mm Oerlikons, or 2-40mm Bofors, or 1-20mm and 1-40mm |
| Light Weaponry: 6-mounting points for 30-calibre, 50-calibre, or combination |
| Torpedoes: 10-21" torpedo tubes (6 bow, 4 stern); 24 Mark-14 torpedoes; Mark III Torpedo Data Computer |
| Engines: 4 GM-Winton V-16, or 4 Fairbanks-Morse 9 or 10-cylinder opposed-piston diesel/generator sets. |
| Motors: 4 DC high-speed electric motors, reduction gear drive, two per shaft |
| Radar: Short range SD air detection radar; SJ surface search radar |
| Sonar: JP hydrophone, upper deck; JK/QC, QB Sonar under bow |
| Wartime Modifications: Conning tower cut down to reduce silhouette, forward AA gun platform added, progressively heavier deck gun fitted, enhanced sonar and radar, bathythermograph, LORAN. |
It was customary to give the name of the boat and class the Americanized pronunction "gate-oh," rather than the Spanish form "gaht-oh".
