After passing through almost 200m of ultramafic rock, drilling is proceeding slowly through the tough cherts that make up the Buck Reef. We started with NQ core equipment. i.e. a hole size 75.6mm and core size 47.6mm, and with it our advance in the chert was a magnificent 3m in 24hrs. We subsequently changed to a TNW bit which has the same hole size of 75.6mm and a core size of 60.5mm, giving us the double advantage of larger core and a faster rate of drilling (the reason for starting with NQ is that it is a wireline technique which, when used in normal rocks, is a very much faster drilling technique than TNW which requires that the entire rod string is withdrawn after each run). The thin-walled bit allows three times the penetration in the chert. A picture of the different core sizes is attached for information). We are now drilling at about 8- 10m per day and have reached a depth of 250m, about 50 m into the chert.