It seems to me the ships that have 'Quakers' are also ones who have been used for Movies. Most likely the Quakers were bought by the production companies (cost vs effect) and then 'donated' back to the ships. This is the case with the Rose (aka HMS Surprise). Even though the Rose came with full firing replicas, the production company choose to purchase larger Quakers for visual effect (the screen adds 10lbs) but with cost savings (no recoil, less safety issues). However for the purposes of live re-enactment, Quakers don't do it for the VIPs and most of the Quakers become stagnant movie props. Anyone for some fiberglass door stops for your barn?