I have now collated all the feedback and passed it on to Martin Thomas who is editing the new edition of "Heavy Weather Sailing".
It was great to hear first hand accounts from Randall Reeves, Jeanne Socrates, Tony Gooch, Tim Good and Susanne Huber-Curphey among many others. The new edition of HWS will appear in due course but should anyone be considering venturing into the more extreme conditions and want to know more about the JSD I have attached a copy of my summary below.
I would also like to hear of some of the more technical aspects from anyone that has used the JSD .
Boat length and weight
number and type of cones
approximate distance from the stern to the first cones
Tail weight used

Thanks Steve that’s brilliant. We have bolted on stainless chain plates for ours but never used it in anger.