On: Build your very own submarine starting from $50,000

[rogerbinns]

Note that this sub is open to the water in the bottom which means that the air pressure is the same as the water pressure. That means you have to take all the same precautions as divers in terms of depths, ascent rates and making sure you don't get the bends.

[TrevorJ → rogerbinns]

Interesting, that is a great point - doesn't this make it a diving bell technically then?

[rogerbinns → TrevorJ]

Yes, their web site specifically mentions that. There is no hatch on the top - you have to enter from underneath. They point out that a good hatch would cost almost as much as the whole "submarine".

[its_so_on → rogerbinns]

if it ever turns over, does all the air bubble out of it?

[johnpmayer → its_so_on]

Reading through the specs, it seems that it's designed with that in mind - the center of mass is much lower than the center of buoyancy.

[david_shaw → its_so_on]

Yes. That's certainly something that would need to be taken into account when in use.