Cocklebiddy Cave is currently Australia's longest single tunnel cave. The only longer cave is Tank Cave in the Mt Gambier region, which has a total length of over 8km in a honeycomb pattern. Our trip this year was designed with the main goal of getting Craig Challen into a position where he could lay some new line at the end of Chris Brown's epic dive in 1995. Using closed circuit rebreathers and some specially developed lithium ion batteries in our scooters, we set up the cave over a period of 9 days before we were ready to send Craig to the end!. Harry and Craig set off for a 16 hour return trip to the end of the cave. Near the limit of previous penetration, Craig removed his rebreather and forged ahead initially on side-mount open circuit, then on a single no-mount tank with an H valve. Harry waited in the darkness for 70 minutes for his return. As well as laying some new line, the team also managed to mark 4 separate pinger/GPS locations in the 3rd sump which will assist Tim Payne and his mapping group. Everyone on the trip achieved a personal best with 4 divers reaching Toad Hall. The new batteries gave an awesome burn time of 3 hours; Doug Friday and Geoff Paynter produced some spectacular still and video images. Ken Smith swam far into the 3rd sump to retrieve the pingers. All in all a spectacularly successful and enjoyable trip!