Hi all,
the system as pictured by Peter is the same as I had on Twice Bitten, which is now at Peters club also. great system easiest, latch and unlatch of any I have used.
Although the rotate your mast systems are OK, once you work out if you need rope behind ring or in front to get it to hook on and usualy there is a best side to rotate it towards to unhook as well, but once you get used to them they are OK if designed correctly, which the AHPC one is.
I guess I like the continuous halyard type as pictured by Peter as it is fool proof on and off regardless of wind flapping sail and you don't have to tuck halyard away. Mind you the A class sailors don't like the weight of the halyard up the mast never mind 2 lengths with this system, but I can live with it

. Don't think that Bob would though