This submarine originally sank in Portland harbour due to an explosion and subsequent fire, which killed some of the crew. She was salvaged and sunk in her present position as a Sonar target and makes an excellent dive. The Sidon is upright and although in tact there are many holes in her casing, which have attracted much fish life. One of my memories of this wreck was being on the conning tower and looking up to see the dive boat 25M above me a truly stunning sight for our waters. Max depth 36M