Please forgive me if these things are already old hat, I just cottoned on to them today.. I've ordered a pair for my 'Foxy Noxy Mariner' (a Nox 600 that got flooded but has since dried out and now works fine again as my main dive detector).. The ONYX is waterproof down to 50 meters.. It was dreamt up by Detect-Ed and SeaGhost Engineering.. On paper they sound good, can't wait to give them a good flogging in the wild.. I'm already in love with the curly cord, it'll make a nice change from the lon