Difficult watches


The dim ROV control room during the 0400-0800 watch. Photo Javier Escartin.

Dive 417 began with reinstalling the modules on the SEAMON East node. The first step was to locate a small area near diffuse flow areas that could accommodate the NOCS in situ chemical analysers — named IronmanS because they can analyse iron and manganese. Once the temperature has been measured (on the order of 15 to 20°C), IronmanS was removed from SEAMON and deployed several meters away from its docking station.

The monitoring module TEMPO was next in line to be installed. It was the steep terrain that had caused the module to be so unstable, so the ROV landscaped the area by moving some big rocks. After a quick scan to check that the module was in good condition, Victor put both TEMPO and the tip of the chemical analyser CHEMINI in place. A final test on the Wi-Fi link revealed a problem with the storage of the video recordings. After many tests, TEMPO was left in acquisition mode until the next dive. Since then, Julien and Tanguy have been racking their brains and contacting their colleagues in Brest to figure out where the problem could be.

The rest of the dive was dedicated to recovering Javier’s and Thibault’s temperature probes, moored in 2009. This is hard work because some of the probes are deeply embedded in newly formed sulphides. The visit to the White Castle vent site really impressed Jérôme: “It looks like a witch lives in there!” he exclaimed at the end of his ROV watch. The top of this small hydrothermal vent is covered with chimneys that belch black smoke.

This morning, a new twist in the cruise’s weather saga: the weather conditions will prevent us from recovering Victor and from mooring the BOREL relay buoy... Yet another plan B to draw up...

Don't forget our section instrumentation!


Deploying the IronmanS chemical analyser. Photo Victor

The front of the TEMPO monitoring module. Photo Victor

Measuring the temperature in a black smoker on the White Castle vent. Photo Victor



The summit of a hydrothermal vent located in the Lucky Strike vent field. Photo Victor.



Deploying a HT probe on the Montségur hydrothermal edifice. Photo Victor.