The usual research.
Notes to self:
Displacement: 2,730 tons (surfaced); 3,960 tons (submerged)
Speed: 17 knots (surfaced); 8-1/2 knots (submerged)
Range: 25,000 miles
Torpedoes: 4-21" torpedo tubes (bow), 2-21" torpedo tubes (stern)
source:
http://www.fleetsubmarine.com/narwhal-class.html
Displacement: 2730 tons surfaced, 4050 tons submerged
Speed: 17 knots (31 km/h) surfaced, 8 knots (15 km/h) submerged
Range: N/a
Torpedoes: six 21-inch (53cm) torpedo tubes (four forward, two aft; 24 torpedoes); 2 x 6 in (152 mm)/53 caliber guns, 2 x0.30" (7.62 mm) machineguns
Source:
http://en.wikipedia.org/wiki/USS_Narwhal_(SS-167)
Displacement: 2730 (surfaced); 3960 (submerged)
Speed: Surfaced, 17.4, Submerged 8.5
Range: 18,000 miles at 8 knots
Torpedoes: 2 6-inch/53 Mk15 deck guns, 6 21-inch torpedo tubes (4 fwd, 2 aft), 4 external 21-inch torpedo tubes (2 fwd, 2 aft); 1942
source:
http://www.globalsecurity.org/milita...-167-specs.htm
Displacement: Surfaced: 2,730 t., Submerged: 3,960
Speed: Surfaced 17 kts, Submerged 8 kts
Range: Fuel Capacity, 182,778 gal
Torpedoes: four 21" torpedo tubes forward, two 21" torpedo tubes aft, four 21" torpedo tubes topside, 24 torpedoes; two single 6"/53 deck gun, two 30 cal. mgs
source:
http://www.navsource.org/archives/08/08167a.htm