There will often be a large school of bullseyes in and around the cave mouth.  Moving further in the ground is littered with empty lobster shells the result of bullrays feeding on the local lobsters.

There is a vertical chimney about 10 meters into the cave.  At the base of the chimney, the entrance passage continues for another 3 meters becoming gradually lower and usually sheltering a large wobbygong.

Ascending the chimney, make sure you shine a torch into the crack running up the far wall.  The crack is filled with lobsters, slipper lobsters and banded shrimp.  

At the top of the chimney, there is slit heading in the direction of the deep entrance and leading to a blow hole on the island.  The slit is mostly too narrow for a diver to fit.  The marine grown encrustation in the slit is relatively pristine due to not being subject to diver traffic and divers should avoid penetrating this area to avoid unnecessary damage.

Ascending above the chimney to the cave roof you will find a pocket of trapped air.  The tradition is to at least once ascend into this pocket and take a breath or two without your regulator.  Be careful if there is any swell as the pressure waves through the water will cause rapid increase and decrease of air pressure in the air pocket, potentially causing disorientation and affecting your equalisation.

From the top of the chimney continue heading away from the deep entrance.  You come over a large boulder wedged in the crack.  There are always lobsters sheltering to the left between the boulder and the wall.  As you come over the boulder, you will reach sandy bottom.

On the left will be a slightly overhanging vertical wall.  On the right the rock slopes up to the roof.  There are often bull rays feeding on lobsters around the boulder or cruising over the sandy bottom.  A turtle makes its home midway between the boulder and the shallow entrance.

Towards the shallow entrance the walls are decorated with pink and yellow coral polyps, feather stars and a huge variety of nudibranchs, sea spiders, shrimp and other macro critters.  As you approach the light zone the density of growth increases with more and more sponges and other soft corals.

Getting closer to the shallow entrance, you will find more schooling bullseyes and resting wobbygongs.  Moray eels hide around the boulder pile.  Another sand bottomed, wedge-shaped gulley runs from the shallow entrance at 12 meters depth.  Again grey nurse sharks often cruise in the gulley and the shallow cave mouth.

Heading South from the gully will lead over a gently curved ridge and around to the southern edge of the island.  From the south-eastern corner of the island heading East, the slope gets gradually steeper until it becomes a sheer wall encrusted with red and green algae, barnacles, short hydroids and hydroid ferns.

From the south island wall heading out there are a series of ridges separated by sand bottomed gutters, perfect territory for grey nurse shark aggregation.  During the peak of the grey nurse mating season it is common to find 50 or 60 sharks spread across these gutters. 

Following the western canyon wall leads up over another ridgeline and straight into the strong East Australian Current.  Here it is necessary to use reef-hooks and make sure you have gloves on your hands as movement is hand over hand to drag yourself down the steep slope against the current.  There are large blocky orange sponges and fluted trumpets projecting from the walls.  As you reach the bottom of the wall, you have been following a ledge.  You reach a boulder pile in a sandy gully.  Cross the boulder pile against the current. 

Crossing a final ridge leads to the base of another canyon.  Stop, hold on, and watch school of pelagics and huge marine species fly past in the raging current.  Species seen at this point include a whale shark, hammerhead sharks, and bronze whaler sharks.

Land of the Giants is not a dive for inexperienced divers.  It is one of the most challenging diving experiences on the East Australian coast.  The dive requires plenty of gas and planning for diver recovery in strong current.

The rock reef surrounding Green Island is encrusted with short hydroid ferns, red and green algae, barnacles and tube worms.  Eagle rays and bull rays often cruise past over the sandy bottom edging Green Island and its reef.

Green Island attracts grey nurse sharks and a range of schooling pelagics, temperate reef fish with some tropical species.  You can often find loggerhead turtles, green turtles, moray eels, octopus and lion fish.

There is mooring buoy on the northwest corner of the island, with its base at on the low reef at 15 meters depth.  Follow the low reef east then south around the island.  There are sporadic boulders littering the coarse sand and gravel bottom around the northeast corner, which is a favourite spot for grey nurse sharks.  

Continuing south along the eastern edge of the island, the reef slopes down to the sand at 18 meters depth, gradually becoming steeper until becoming a sheer wall with overhangs towards the southeast corner. 

Visibility ranges from 5 to 15 meters.  Water temperature ranges from 17 to 24 degrees.  The prevailing currents tend north to south.