Fleet Snorkel Program

When the Navy realized that it would not be able to fund all the GUPPY conversions it desired, it devised the Fleet Snorkel program (SCB 47B) as a means of adding the minimum necessary modifications to fleet boats. The Fleet Snorkel modernization added a snorkel, a streamlined sail, a higher capacity air-conditioning system, and a more powerful electrical system. The deck guns and auxiliary diesel were removed. Unlike the GUPPY conversions, the Fleet Snorkel boats retained their original deck structure, bow, and storage batteries. Submerged performance of the Fleet Snorkel boats was therefore significantly inferior to any GUPPY conversion. Despite their limited features, the Fleet Snorkel boats served almost as long as the more modern GUPPY boats. The USS Irex (SS-482) was the first conversion in 1947. Three boats, Piper, Sea Owl, and Sterlet, received a large BQR-4A bow sonar.

(USS) Sea Cat (SS-399) Balao

(USS) Sea Owl (SS-405) Balao

(USS) Sea Owl (SS-405) with BQR-4A Bow
(USS) Sennet (SS-408) Balao

(USS) Piper (SS-409) Balao
(USS) Torsk (SS-423) Tench

(USS) Argonaut (SS-475) Tench
(USS) Runner (SS-476) Tench

(USS) Medregal (SS-480) Tench

(USS) Irex (SS-482) Tench

Specifications:

312' length
27' 4” Beam
17' Draft
2,040 tons Surfaced Displacement
2,410 tons Submerged Displacement
4,610 SHP Diesels, 2 Shafts
4,610 SHP Electric Motors, 2 Shafts
18 kt surfaced speed
9 kt submerged speed
400 ft Test Depth
81 to 83 crew

Weapons:

6 x 21” TT Bow
4 x 21” TT Stern
24 or 28 x 21” Torpedoes (Depending on whether Balao or Tench was converted)