Merv is a giant grouper who whose home is Coral Bay. Before the boating facility was built, he could often be found hanging around under various commercial fishing boats just off the beach, presumably in the hope of a free feed. It has not been unknown for Merv to have a bite of an ankle dangling in the water off the Marlin board of one of them.
Since the construction of the boating ramp Merv has moved and can sometimes be seen under the jetties.
Merv is a big fish, quite a sight when encountered snorkelling!
More recently - another grouper, named Mervette has been spotted.
From Wikipedia -
The giant grouper (Epinephelus lanceolatus), also known as the brindle bass , brown spotted cod , bumblebee grouper and as the Queensland grouper in Australia, is the largest bony fish found in coral reefs, and the aquatic emblem of Queensland, Australia. It is found throughout the Indo-Pacific region, with the exception of the Persian Gulf. The species can grow as large as 2.7 meters (9 ft) long, weighing up to 600 kg (1320 lb); there are unconfirmed reports of it growing much bigger. They are fairly common in shallow waters and feed on a variety of marine life, including small sharks and juvenile sea turtles.
This giant fish is similar to an Estuary Cod and colour changes with age. The giant grouper has a large mouth and a rounded tail. Juveniles have irregular black and yellow markings, while adults are green-grey to grey-brown with faint mottling. There are numerous small black spots on the fins. view original wikipedia article
Other sites you may care to check Australian Museum and the NSW dept Primary Industries site have more about this species of fish.