If we don't get to do or see anything else for the rest of the holiday it won't matter, it's already been worthwhile."
That was a travelling companion's comment as we powered back to the 24m catamaran Odyssey, anchored inside Clerke Reef as the sun was setting on the first of a seven-day diving cruise at the Rowley Shoals.
He was sitting on the gunwale of a 12m dive tender, still on a high.
On our first day, we had dived at a site called the Aquarium, drift snorkelled on an outgoing 10m tide and swum with a humpback whale while she fed her calf.Surely it couldn't get any better.
The Rowley Shoals is made up of three coral atolls on the edge of the continental shelf about 260km west-north-west of Broome.
They were named in 1818 by Captain Philip Parker King. He named Mermaid Reef, the most north-western of the three atolls, after his ship.
The middle shoal was named Clerke Reef after Captain Clerke, who had reported it from a whaler some time between 1800 and 1809, while the south-western shoal was dubbed Imperieuse Reef after the vessel from which it was sighted by Captain Rowley in 1800.
All three atolls, which are each about 85sqkm, rise from very deep water with near-vertical sides that form shallow lagoons. Mermaid Reef rises from 440m, Clerke from 390m and Imperieuse from 230m.
They are renowned for their virtually untouched coral gardens, giant clams, inquisitive potato cod and abundant fish life.
There are more than 230 species of coral, including 28 different species of staghorn, and 688 species of fish, including sharks, inhabit the shoals.
Clerke and Imperieuse reefs were declared marine parks in 1990, with the size of the parks increased four-fold in 2004. There are still areas at both these locations where fishing is allowed.
Mermaid Reef has been declared a Marine National Nature Reserve and no fishing is allowed.
Since 1977 charter boats have been taking fishing and diving enthusiasts to this remote location.
It is a 16-hour cruise from Broome over a stretch of water that can become both very rough and windy, restricting the season to around two months, October and November, a year.
And it is this isolation that ensures the Rowley Shoals remains one of the most pristine coral atolls in the world.
It also means that fewer than 250 "tourists" visit the region each year.
After a long night and morning of cruising, fortunately for us on calm water, the first sign of the atoll was a slim white line on the horizon.
The line is Bedwell Island, a small sand island that is home to one of only two colonies of red-tailed tropicbirds in WA, and the only land we will see for the next seven days.
There is also a small island at Imperieuse atoll, but because it is the most heavily fished and the only one of the three atolls that does not have access to the lagoon, Odyssey Expeditions does not include it on the diving itinerary.
As we closed in on Clerke Reef, and Bedwell Island, the colour of the water started to change. It reminded me of the waters around Rottnest Island, only the blues are more vivid and the water clearer.
Standing on the bow of the big cat, which cruises at a comfortable 10 knots, you can see the fish darting over the bleached white sand as they react to the intrusion of the two big hulls breaking the surface and the chug of the diesel engines.
Secured to its mooring inside the atoll, the Odyssey's five-person crew busy themselves, setting up tables and umbrellas on the decks, lowering tenders into the water and preparing equipment for the first dive of the holiday.
It is an early indication of the energy and pace this young crew is going to set for their 16 passengers (Odyssey takes a maximum of 20 passengers) over the next week.
Within an hour we have eaten lunch and are ready for our first diving experience at the Rowley Shoals. The destination is a site called The Aquarium, the only dive site inside the atoll and one of the shallowest.
Falling back into the water, the initial shock of cold that is a part of diving in the metropolitan area was missing. It was more like easing into a cool bath on a hot summer's day and the water was about as clear, with visibility up to 40m.
The visibility was one of the many aspects of diving in the Rowley Shoals that never ceased to amaze.
The variety of corals, range of colours and abundance of fish life in all sizes and colours at the Aquarium was something I had never seen.
As it turned out, it was only a taste of what was to come. For the next six days we dived at least three times a day, and on two days added night dives to the itinerary.
Despite the extreme depths of water we kept our dives to a maximum of 30m, which was more than enough to thoroughly explore the ever-changing landscape that includes vertical walls, gorges, swim-throughs and big caves.
Most were also drift dives, where we allowed the outgoing, or incoming, tide to waft us along the outer wall, exploring on the way.
It was on these dives that the big dive tender was a blessing, picking up divers as they bobbed back up to the surface at various intervals along the wall.
The beauty of these natural wonders is enhanced by soft corals in every imaginable colour, massive gorgonians and coral forests that are home to an unbelievable variety of fish. Trying to adequately describe the fish life is difficult.
It is like being dropped into a giant aquarium owned by someone who did not know what they wanted so they simply added as many different varieties, and colours, as they could.
The shallower water is dominated by tropical fish, with pelagics also cruising just under the surface with sharks, yes sharks, up to 3m and in healthy numbers, patrolling the vast schools.
The first encounter with a black or white-tipped shark takes your breath away. It is hard not to be frightened, imagine the worst.
Like most of the other fish at the Rowley Shoals, they simply ignore you, going about their business, even feeding on other fish. By the end of the week they become just part of the incredible scenery.
We also saw giant clams, big turtles, eels, and in certain areas giant potato cod - big tame fish that will swim alongside you, sit and have a staring competition and even enjoy a gentle rub on their side.
If there is a highlight, for me this was probably it. The potato cod treat the intrusion of divers, with bubbles streaming from the top of the head, as an everyday occurrence. You would swear they even enjoyed the encounter and looked forward to seeing divers descending into their world for a brief visit.The swim with the humpback whale was an unexpected bonus on a trip where each day ended with 16 excited passengers unable to wait to share their experiences of the day.