This is a moment for mad ramblings.
If i had the money to construct/maintain that thing i’d:

• Hire a crew made up entirely of hot asian chicks and/or ninjas. Combination is also acceptable. Hot ninja chicks.
• Make them wear uniforms that have my name on it, maybe even my face embroidered
• Train a small army of dolphins to defend the sub from angry whales
• Hire an angry whale
• Christen the thing “Deathshark”, give it shark decals like jaws etc
• Paint the thing ninja black.
• Fill the thing with traps, in case of boarding by pirates.
• Install a way to electrify the hull in case of boarding by primitive tribes
• Install an unbelievable sound system. On the outside of the hull. When i’m under the ice caps, scubadivers off hawaii will hear creepy music
• Arm the thing. Somehow! Please?

If we all get in on it now we could have a FLEET! Imagine! We could rove the seas, solving environmental problems with our supreme knowledge of the seas!