Oh, you guys disappoint me. Mike Boon was a British caver who was active from the late 1950s thru the 1970s. You might know him from the accounts of early Swildons dives, but he also surveyed (with Tich Morris) the entrance series of Darren Cilau - 'nuff said? Mike went on to fame caving in Mexico when Mexico wasn't cool, did a solo expedition to the back of Castleguard Cave in Canada, and was considered by some to be the best caver in the world... and currently lives quietly in Calgary.