I mean, the depths of the ocean where subs are known to frolic is probably pretty cold.

A_Lurker said:

I mean, the depths of the ocean where subs are known to frolic is probably pretty cold.

World War II subs couldn't go very deep, though.

What was max depth for those subs, anyway? Well... maximum depth where they could maintain hull integrity and return to the surface instead of sinking to the bottom.

Garrus said:
What was max depth for those subs, anyway?

Type B1 submarines like I-19 here were expected to make 100m dives safely.

FJH said:

Type B1 submarines like I-19 here were expected to make 100m dives safely.

That was a pretty typical test depth for subs of that era, yeah. Some of the more advanced models from later in the war could go deeper--the US Navy's Balao and Tench classes could go to 400 feet (~120 m), and German Type XXI U-boats could go to a staggering (for the time) 240 m, but 100 m / 330 ft is typical for the era.

This was potentially awkward in the case of the I-400-class subs, which couldn't safely dive as deep as they were long (100m test depth, 120m length). In a crash dive (inasmuch as those boats could even do something that could be described as a crash dive--they were pretty unwieldy in general because of their size and the weird layout of their superstructure), it was possible for the bow to reach test depth while the stern was still above water.

Mind you, test depth and absolute crush depth aren't the same thing; the record for a Balao-class submarine was 612 ft (187 m) in testing of USS Tang, and some were reputed to have gone even deeper in combat. Still, compared with the test depth of, say, a modern Seawolf-class submarine (ca. 1,600 ft), that's pretty small change.