Hi Joel - There are submarine volcanic vents in Southeast Alaska, but none of them are known to be active at this time. The vents that I know of are not particularly close to Coronation Island. Boat water temperature sensors near Sitka often record temperatures in the 60s and 70s, particularly in shallow waters warmed by sunlight. Thank you for passing on the observations, Cheryl -------- Joel Curtis wrote: "...​received a call from a Sitka resident who is a commercial fisherman. He recorded some unusually warm water temperatures in the vicinity of Coronation Island near what he said was a submarine volcano. Numerous locations that he recorded were over 60F and one was in excess of 71F. His sensor is 6 ft below the surface mounted on his hull. Current SST at the two closest buoys is 54F. -- Cheryl Cameron Geologist, Alaska Volcano Observatory Alaska Division of Geological & Geophysical Surveys voice: 907-451-5012 fax: 907-451-5050