[weird-eye-issue]

Right, so you need the ballast. Which is not inherently part of the capsule. Which proves my point.

[lb1lf]

Well, you need to be able to change the weight of the capsule somehow, otherwise you'd be stuck bobbing at the surface. (Or at the seabed).

The puzzling bit, from what I have gathered, is that the ballast is not fail safe.