H2O Sportz operates out of Hamilton Island in the Whitsundays. They serve snorkellers and divers, both certified and introductory.  Their primary dive site is Bait Reef.  However, they also visit various sites around the Whitsunday Islands depending on the weather. 

 http://h2osportz.com.au/

dive group at Bait Reef      view of dive boat from the sky

H2O Vessel