I did Cocos on the Sea Hunter in October 2005.
FAB
Looking at one of my logs I wrote something like "An OK dive, only saw about 50 white tips"
. I'd done less than 100 dives even by the end of the trip, I didn't find it too challenging.
I don't recall being cold (I'm known as Mrs Cardi) and although it rained a lot, It didn't spoil anything for me as I'm not a sun worshiper.
Channel 5 every day next week at around 7:15 ish is showing Nigel Marvin Shark Island at Cocos.