I have never understood how one gets stuck with the old system, if i lean back to far i can fall right off the boat, of course i dont have a spring piece on my hook to keep the harness in (took it off)
The danger is not being stuck on your trapeze loop as this is usually mobile enough to move out. The danger is getting your hook stuck around a stay or a bridal or any line really...
For example you jump/slide/crash between the boom and the trampoline during a capsize and on your way down your hook catches lets say one segment of your nicely cleated 9 to 1 mainsheet. Your weight, now pulling on both the sheet and the boom, pulls the boat turtle pinning you under until you release that #$%^#@% hook. That's the danger.
