Our day began with a visit of the mayor of Santorini or Thera, and other officials from the island, who were informed about the work of the Aegaeo around their island. We then proceeded to a dive site for the ROV Max-Rover to the south of Thera, but the sea conditions were so rough that a dive had to be abandoned. Instead we went inside the sheltered caldera and a dive was done at about 300 m depth on to the sea floor in the north-east corner of the caldera. Here the floor is covered with yellow to whitish mounds of bacterial mats, that are probably evoling here in an area of hydrothermal activity.

The mounds are up to one meter in diameter
and form cones up to 40 cm in height. The Max-Rover does not have a temperature probe, but we will return to this site with the Hercules ROV in June, to check the temperature of the caldera floor.