What type of submarine can cope with high pressures?

Answer 1

All submarines are built to withstand repeated trips to deep depths, encountering high atmospheric pressures. However, no submarine is without a limit, and in general it's the vessel's construction design and material that determines its crush depth. That's why modern submarine hulls have cigar or teardrop shaped hulls - the spherical design is the strongest (think of an egg).

The strongest alloy for submarine use, titanium, is used by the Russians, though it has its limits. Since it doesn't flex like other boats that use flexible steel alloys that contract and expand with depth changes, their hulls become brittle and more vulnerable over time.

The best design for extreme depths are used by submersibles. While you typically will see a streamlined craft, in actuality the crew compartment is usually a sphere, which again, is the strongest shape for extreme pressures.