Saturday 23rd February

Isis returned from the deep in the early afternoon, after collecting a suite of samples and data for different science teams aboard the RRS James Cook. It was all hands on deck in the lab again to process the samples collected by the latest dive, ready for further analyses ashore.

We are now entering the final phase of our operations: on Monday at 0700h local time our expedition to the deep-sea vents will end, and I will hand over as Principal Scientist to Peter Talling, who will then lead an investigation of the volcano on the island of Monserrat.

After discussions with the ROV team and the leaders of the science teams aboard, our final plan of activity has crystalised. This afternoon the geochemistry team have continued their survey of the waters dispersing from the vents, while the ROV team prepare the vehicle for the last dive of the expedition to the world's deepest known vents.

We may not achieve all our final dive objectives, but it is always better to leave the deep ocean wanting to return for more, and we should have everything we need to answer the key questions that brought us here this time. Every visit to the deep ocean also prompts new questions, and I hope that we will return here again.

In fact I know we shall: we have deployed equipment to record data after we leave, which will be collected by a Japanese expedition later this year, in which we have kindly been invited to participate. With the insights from our dives, we also hope to contribute to a US expedition visiting the Von Damm Vent Field to trial some nifty new surveying technology later this summer.

Before our final dive we need to take stock of what we have achieved so far, and start to consider the shape and content of the final expedition report for our funding agency. Spreadsheets need to be compiled, and any gaps in digital records filled from notebooks, to ensure that we are ready.

February 2013