| Lead Boat: SS-167, U.S.S. Narwhal |
| Length: 371' |
| Beam: 33' 3" |
| Draft: 16' 11" (Surface trim) |
| Displacement: 2,730 tons (surfaced); 3,960 tons (submerged) |
| Speed: 17 knots (surfaced); 8-1/2 knots (submerged) |
| Diving Depth: 300' (test depth) |
| Range: 25,000 miles |
| Endurance: |
| Crew: 9 officers, 10 CPO, 70 enlisted |
| Deck Gun: 2-6"/53-calibre |
| Anti-Aircraft Weapons: |
| Light Weaponry: |
| Torpedoes: 4-21" torpedo tubes (bow), 2-21" torpedo tubes (stern) |
| Engines: 2-2,350 hp diesel; 2-450 hp diesel generator |
| Motors: 2-800 hp |
| Radar: |
| Sonar: |
| Wartime Modifications: Both converted to transport submarines. |
