It is much easier to keep electronics working down there when empty space is filled with liquid instead of pressurised gas (usually nitrogen). It is not the pre

It is much easier to keep electronics working down there when empty space is filled with liquid instead of pressurised gas (usually nitrogen). It is not the pressure, but pressure difference, that matters and liquids are not as compressible as gas is. Edit: just adding a note that I have worked with submarine electronics[1] for a while and can say we even do not know much about what is happening near the shore, not to even talk about the unexploredness of oceans. Quite a lot of HW/SW in use by scientists is far from modern. We need more initiatives like the Ocean Discovery XPRIZE[2] to bring attention to the field. [1] http://www.flydogmarine.com http://www.flydogmarine.com [2] https://oceandiscovery.xprize.org https://oceandiscovery.xprize.org