We're heading to Cairns mid-September to snorkel the GBR. We really want to do one of the liveaboards and prefer the 3day, 2night trips. I'm concerned though that as snorkelers we won't have the best access to shallow reefs on the dive trips. I know that most of them say they cater to divers and snorkelers but, does anyone have a recommendation for the best tour specifically for snorkeling? Thanks for any input you can provide!