We are both biologists and a little bias toward the deep-sea critters, but the deep ocean contains a wealth of geological discoveries, after all, it is the geology which creates the deep sea.

We catch up the latest news, including life discovered 100s of km under the ice, slowing water currents, vampire squid history and the rules of naming something new, be it a species or an undersea feature.

We then have a chat with geologist and explorer (and friend of the show) Heather Stewart of the British Geological Survey about the geology of the deep sea and how we produce maps of the ocean floor. Why do people talk about how little of the ocean has been mapped when we can clearly see it is all mapped on google earth? Where is that data from?

What about some of the more unusual features that we see on the deep seabed in Google Earth, are those roads and pyramids? I have a chat with ‘my mate Dave™’, David Howell, about marine archaeology and looking for sunken human settlements.

Finally, we hear from Don Walsh, who recollects the time he used the bathyscaph Trieste to deploy devices to listen out for nuclear tests.