With the disappearance of the Malaysian plane in one of the most hostile parts of the deep ocean, it has highlighted one of our engineering black holes. The deep ocean. It does not seem like we have many vehicles that can cope with the pressure of staying down at those depths. While there is a constant coverage of the earth from above the surface, there seems very little activity monitoring what goes on beneath the oceans. I guess the technology is driven by the oil industry and mostly we work well at depths that we can drill at. I can't imaging they are interested in two mile deep oceans in the most inhospitable places on earth. Not yet anyway... So thought it might be interesting to look at what is possible, what the problems are and what we do know about these deep oceans that cover most of the planet.