In 2007, I have dived with submersible Thetis of HCMR in the northern part of the crater (500m depth) , just where the active hydrothermal vents are excisted..in 2010 and 2011 aboard E/V Nautilus (www.nautiluslive.org) we have investigated the crater walls and the hydrothermal vent field with ROVs..the first results have been published in the Special Volume of Oceanography (http://www.tos.org/oceanography/issues/issue_archive/24_1-supp.html) and presented in many International Conferences. We have written scientific papers (accepted-in press)..but the most important is that we have informed the people of Santorini about our results (October 2nd 2010-Bellonio)..the more we know about this active submarine volcano..the more we are impressed with its power!