"JAXAshby" wrote in message
...
The quick-release shackle has a nice
lanyard on the release pin and it works smoothly. I have never had one
of
these ... open accidentally.

maybe *you* haven't, but most of the sailing world has.

snap shackles are thoroughly considered to be no-no's on tethers because
they
so often come open when the lanyard gets snagged on something.

Same thing with the aforementioned snap-carabiners. I'm a (not very
accomplished) rock climber of sorts, and a snap gate crab is NEVER used as a
primary means of hooking into a line, and the use of a locking (screw gate)
crab is frowned on as well- knots are the only safe way, in rock climbing.
Of course, it's a bit of a different situation; if the rock sinks you've had
it anyway