on the hydrographic chart . Yet in 2011 a survey could not find the wreck in the charted position . It was deemed ‘ Dead ’ and removed from future charts .
Not to be discouraged , Kevin and Bob realised that the wreck must be there and each year when Bob was operating out of Mull , he would spend some time working with Sula Diving , conducting a sidescan sonar search of the areas of interest . These areas were HMS Circe ’ s logbook position ; the U-boat mine laying position ( from the German U-boat archive ) and the UK Hydrographic Office ’ s list of ‘ Dead ’ positions .
Sonar surveys started in 2017 , with no apparent success in that year or the next . It was noted that there were many rocky outcrops that could hide wreckage . Bob returned in 2021 and in his words , they had “ a bit of luck ”. During a grid search , Clasina made a turn and obviously the sonar ‘ fish ’ also changed direction . When reviewing the scan from this moment , Bertrand Taylor of Sula Diving , who was the sonar operator , felt that there was a wreck partially hidden by a large rock .
The Gasperados have some history in finding and diving Naval shipwrecks . We are trying to operate in a sensitive way respecting any site we dive . Bob and Kevin suggested to Steve that our team might be interested in helping them finally solve the mystery of HMS Jason . Bob also suggested that in honour of Jason we rename ourselves ‘ the Argonauts ’ for the duration !
So , under a new team name , Steve approached the divers booked onto the trip . Bob had estimated the wreck was approximately 90m ; not everyone was comfortable diving to that depth so early in the season . However , a good number of us had kept our skills going over the winter and dodged Covid . There was a team of eight ready and able to dive HMS Jason . They would be supported and documented by the remaining four , with Steve Ashton of
Ilfracombe SAC acting as Dive Supervisor for the two planned Jason dives . Bob would also facilitate suitable diving for those not diving Jason once operations were complete .
We had a plan , or at least the start of one . Steve Mortimer prepared a Standard Operating Procedure ( SOP ) document , we reviewed and amended this until we were all happy . HMS Jason would be dived in buddy pairs operating a group bailout scenario with a lazy shot decompression station complete with a bailout cylinder of 80 % nitrox on the 6m bar . Divers would carry the equivalent of two Ali 80 cylinders each with deep bailout , travel bailout and shallow bailout shared between each pair . The 80 % was only available at the deco station or as an emergency drop bottle
( requested by use of yellow dSMB signal ).
We were expecting the water temperature to be approximately 7 ° C , so we ’ d be limiting the dives to no longer than 150 minutes . This would allow us to spend 20 to 25 minutes on the wreck .
Dive ! Dive ! Dive !
I took a couple of days to head north , passing a glorious Loch Lomond , surrounded by snow-capped Scottish peaks , finally arriving at Dunstaffnage Marina , where we all met up to board Clasina .
The first day of the week was a check-out , diving Mull classics Breda and Hispania ; I was pleased to see the Hispania looking stunning in 12-15m viz . It was good to check all our kit was functioning and that
Steve and Barbara Mortimer getting ready to dive
Sidescan sonar trace showing varied seabed features . The area of interest is circled , with the red line showing a likely wreck site
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