The interior of the submersible is kept at surface pressure, so you'll be fine. (When diving in shallower waters, in a suit, this would be a concern; however,

The interior of the submersible is kept at surface pressure, so you'll be fine. (When diving in shallower waters, in a suit, this would be a concern; however, as you are at (or very close to) surface pressure throughout the dive - no problem.)