A deep sea mission of genuine exploration

From being a totally unimaginable feature of the deep ocean throughout most of human history to being shown live on global television earlier this week, hydrothermal vents have never been so well understood.

Now back on dry land after broadcasting on the latest work on the research ship James Cook in the Cayman Trough, I'm still picking up messages from people amazed at getting such an extraordinary vision of the reality of the deep sea.

Technology is transforming the way in which we can view our planet. The star of the show is ISIS, the remotely-operated vehicle equipped with HD cameras despatched as an emissary into the unlit depths.

With remarkable accuracy, the pilots on the James Cook used an acoustic navigation system to "fly" the robot over the rock three miles (4.8km) down towards the oases of life thriving around the vents.

The clarity of the images was astonishing - laying bare everything from the spindly grey-brown chimneys, rising at crooked angles, to the violent pitch-black jets of superheated water to the ghostly swarms of blind shrimp.

It's often said that we know more about the surface of the Moon or even of Mars than we do about the two-thirds of our planet covered by water.

Slowly that's changing, but rather like a torch beam picking out features in a darkened cave. Satellites give us a broad overview of the ocean floor, ISIS and other robots give us the detail.

I write this from Grand Cayman waiting for my flight home. The sea is flat and gives no clue about what lies below.

The UK scientists and crew of the James Cook are deploying the ISIS again right now. Its cameras spotted an oceanic white-tip shark during the descent.

This is a mission of genuine exploration. Who knows what they'll find next?