James Cameron has channelled his passion for diving into several works, and was awarded the 2004 Hans Hass Award for his contributions to science and technology. Leslie Leaney introduces our Pioneer of the Week.

Still much remains unknown, although much has been discovered, in our oceans. Through geo-mapping and political arrangement, there are officially five – each with their own biodiversity, topography and quirks. We break it all down for you.

Deep in the ocean is where things get really interesting. Descend to below one kilometre to the bathypelagic zone and the creatures take a weird turn, descend even further to 11 kilometres – the bottom of the Mariana Trench – and marine life becomes surreal.

Known as having the poorest living conditions for any vessel of war, the German U-boat was a forbidding deep-sea carrier and an expert in sneak-attacks on merchant convoys and Allied warships.