But for those of you who have not had the pleasure yet the image below is of a CTD (Conductivity, Temperature and Depth Sensor) with a carousel of niskin bottles.
The bottles are used on the way up, each bottle is "fired" at different depths to collect a water sample which can then be analysed on the surface.
There is more information here written by the official science communicator on board.
It was also interesting from the point of view of an observer to see how different life on board is for the crew of a research vessel than say a cargo or cruise ship. There are a whole range of new skills to learn, from just working with scientists, to dealing with some sensitive and occasionally finicky pieces of equipment.
All up our cast went really well, we got data that looks appropriate for the region and that information can be used to calibrate our soundings.