Aqua blue seas all the way to a shimmering horizon, day in and day out. That was the way I imagined it would be - and it was!

Our entire eight day trip to Rowley Shoals, 300 kilometres north-west of Broome, Western Australia and return was ‘...absolute magic’.

But, this was no ordinary diving trip. This was a trip to monitor the impact of industrialisation and agricultural activities on our reef, oceans and the entire planet. Yes, it was a research expedition requiring many long hours of work above and below the water. But hey! who would want to work in any other office, especially if you are a diver.

The Western Australian Marine Science Institute co-ordinated the eight person team of scientists, support crew and volunteer divers for the expedition. The team joined three crew from the WA Department of Fisheries vessel, the PV Wallcott and ventured to three tiny atolls that form the Rowley Shoals Marine Park in the Indian Ocean.

The pristine coral atolls, situated on the edge of the world’s widest continental shelf, rise vertically more than 400 meters from the ocean floor. The depth was something we were very aware of, often seeing the reef edge disappear into the abyss within a boat length of passage from each lagoon exit.

The endless visibility aided our endeavours to first locate and then work on collecting core samples from Porites Coral Heads. The team, headed by Professor Malcolm McCulloch, locate Porites Coral by skimming over likely areas of reef on a manta board towed behind the dive boat. The sites are marked by a buoy and a GPS co-ordinate is logged.

Only the best coral heads are selected. The colonies of choice are hemispherical or helmet shaped, as large as possible and have a smooth surface. These criteria assist with ageing the coral heads which amount to 1 cm growth per year. Counting the rings of coral growth is similar to identifying the age of a tree by growth rings. Porites Heads with obvious bio-erosion from sea creatures were excluded. As you can imagine, the selection process is extremely important - no time can be wasted drilling core samples from unsuitable Porites.

Some of the corals, especially those located inside the lagoons, were extremely hard and took considerable time and effort to extract the samples. The team appropriately nicknamed them as ‘Kryptonite Coral”. To collect the samples one of the team members positions a core locator in a level position over the a central smooth section of the coral head. On this expedition we used a drill driven by compressed air supplied from a bank of scuba cylinders on the dive boat. The drill is mostly assembled topside before lowering it to the awaiting divers. Adjustment tools and adjunct drill equipment are positioned near the divers for easy access.

The coral is collected at half metre intervals using an extractor rod that is pushed on to the top of the core and twisted. This action was generally easy but occasionally was very challenging when drilling the kryptonite variety. Penetration deeper into the coral is managed by attaching additional coring rods. The length of continuous core can be quite surprising; sometimes we managed in excess of 2.5 meters in overall length from a single head. That represents over two hundred years of the earth’s environmental history - from pre-industrial revolution to the present day.

Professor McCulloch and his laboratory team will now spend considerable time analysing the Rowley Shoals samples and compare them to those collected from reef systems elsewhere. Samples from Australia’s Great Barrier Reef were significant in demonstrating a link to flooding events on the east coast that resulted in the samples from the outer reef, containing mineral deposits associated with land degradation adjacent to major rivers. Rowley Shoals will provide a contrast - there are no nearby lands or rivers.

Although I regularly attend reef life and fish identification surveys, I was totally blown away by all the research activities that took place simultaneously. I was delighted to observe and participate in them all. It’s a whole other world, different to anything that I have ever experienced.

Peter Holterman, a PhD student from Germany is an oceanographic researcher. Of all the people on board, he seemed to have the toughest job, all-be-it, a very interesting one. On the way out to the atolls Peter remained on duty all night to deploy a range of equipment to look at temperature variations in the water column and at the surface. He sent his equipment to the ocean floor almost hourly during our sixteen hour journey. The activity was repeated between Mermaid and Clerk Reef and back to Mermaid and then on the return journey to Broome.

Peter also deployed equipment while at Mermaid reef to obtain data on vertical water flow (undersea waterfalls) within these systems. The diving team, consisting of Steve Blake, John Johnstone and myself, were responsible for adjusting Peter’s equipment and for its recovery back to the surface.

Our diving roles also included taking underwater video and still footage of deployed equipment as well as the core drilling process itself. John and I were responsible for managing diving activities and dive planning for all divers.

While at Clerke Reef we explored the channel on an easy drift dive to take footage of the flora and fauna that inhabit this unique reef system. The channel is punctuated by coral bommies that drop from the surface down to thirty plus metres. Simply, you could describe the site as an aquarium. Tiger sharks were spotted and schools of large fish were everywhere. Multiple canyons and swim-throughs created by large fast moving tides implanted a feeling of awe at nature’s power.

On one of our last drilling excursions we virtually sat on the edge of a four hundred meter drop-off - no room to loose gear over the side. I was told that the wall dive at this site is rated the best in the world - I would agree. Although I did not see them, schooling hammerheads amongst other pelagics often cruise past. I guess the only thing I can do is go back one day and enjoy the area as a recreational diver.

We all had chores aboard the Wallcott. After-all, it is a working fisheries vessel. Apart from sharing the usual cooking and housework we undertook watches on the bridge, to assist the watch skipper lookout for other vessels and whales while underway at night. It was a fantastic opportunity to chat with the Wallcott crew, find out how the vessel operates and feel like you are apart of the adventure.

Would I do it again - you bet I would!

I had little time to explore the Broome region but I did manage to visit the famous Cable Beach. This very welcoming stretch of coastline is inviting to those wishing to soak-up the sun and go for a swim. Beware the Irukandji boxfish, they are common in the region especially in the hot season so take note of the warning signs and swim in the patrolled areas.

The township of Broome is not big and the place is filled with pearl and jewellery shops - just as you would expect from a pearling region. I was in the market for a gift for Paula so the choice of jewellery made my task easy. I did not have to go far. Right next to the tourist information centre I found The Courthouse Collection boasting a marvellous arrangement of Bridget Liddell designed and created pieces.

To get a real feel for Broome and it’s history of pearling don’t go past the Broome Museum located in Robinson Street. The Broome Visitor Centre staff were very hospitable and eagerly assisted me with directions. They are also able to help with tour bookings and accommodation.

For adventure diving to Rowley Shoals visit:

Unreel Adventure Safaris

The Great Escape Charter Company

Odyssey Expeditions