By David King
Saturday 5 June 2004. Four boats belonging to members of the Sydney Project dive team moored over the Coolooli wreck off Long Reef outside Sydney Harbour.
Lying on its side at 48 metres, the Coolooli was hardly a deep excursion for members of this technical diving team. Their credits included a 111m dive on the Peak of Sydney wreck, a 97m dive on the Cumberland wreck, and a nine hour dive in the Cocklebiddy Cave system under the Nullabor Plains. It could have been a training dive or a routine check on the wreck except for an unusual guest: Sacha Dench, former UK and current Australian freediving champion who coached and led the Australian freediving team to last yearâs Pacific Cup Championships.
She was, in fact, the reason why the boats had gathered at this site, for it was her wish to prove she could dive and explore the sunken bucket dredge with nothing but a single breath from the surface.
If she pulled it off, it would be quite possibly the deepest freediving exploration of a wreck yet made in Australia.
âPossiblyâ, because no one knows what a bunch of spearos might have done for fun without anyone to ratify their achievement. All sorts of stories get told at pubs and parties. But this was to be an official attempt with safety divers, video and still photographers, medical support, and the backing of Australian Geographic magazine.
The dive was planned by Sacha and Sydney Project team leader, Samir Alfathi. It was not easy to organize.
As Samir explained: âIt took five dives on the Coolooli to find a suitable place for her to swim through, then to mark these spots for down lines to be secured. I also took Sacha down on scuba to show her the route, and then had to show it to the other divers as well.â
Let downs and rearrangements threatened to sink the attempt and kept Sacha in a state of anxiety until the night before the dive.
âIt was pretty stressful,â she recalled âBy morning, I just wanted to get out there and do the thing. Iâd prepared physically for the dive so got over the stresses and discomfort of going to depth at speed and spending time at depth with my lungs totally compressed.’
âI also knew I had an amazingly competent and professional bunch of (support) divers.â
Fellow freediver Dave Goldie had devised a hand-held weight to assist Sachaâs descent, and Sydney Project team member Dave Apperley had positioned an emergency lift bag to shoot her back to the surface if she was in trouble. Dave also came up with the idea of giving the support divers tap sticks so they could let each other know when Sacha was passing.
It was about midday when Sacha entered the water for her warm-up dives over the Coolooli â the first to 20m where she remained for 3.5 minutes, and the second to 25m where she remained for a similar time. She then spent about a minute floating on her back in the 1.5 to 2m swell and breathing up for the dive. The support divers were in position; visibility was in the 20 to 25m range.
âMentally, I was just looking forward to seeing the wreck,â Sacha recalled. âI was excited but calm.â Then disaster almost struck.
âDue to the tight guide rope and the swell, I was pulled underwater in the middle of my last breath and took in water. I was about to let go of the weight (and abort the dive), but the timing had to be so strict with the scuba divers and their limited bottom time that I decided to just go for it. After about 20m, the desire to cough vanished.â
Four freedivers accompanied Sacha from the surface to 20m where she passed two divers on open circuit scuba. Another safety diver was at 30m, and three more divers using rebreathers on trimix were waiting for her on the wreck.
For Sacha, plummeting into the deep with support divers clacking their tap sticks as she went by was like âhaving a crowd cheer you on in a marathonâ.
On reaching the wreck, she let go of the weight and swam the pre-marked route which took her down the centre of the vessel, past the buckets, and through the bridge. The deepest point of the dive was 44m.
âWhen I finished the route, I had plenty of air, so had time to go further, play with a cuttlefish, get out my Australian Geographic flag, and swim past the videographers,â Sacha said. She then returned to the main shot line and swam back to the surface.
âEach dive was well within my limits. I was not gasping at the surface or even near to itâ Sacha said. âNowhere near blackout either.â
Sacha did four dives on the wreck, each lasting about 2 minutes 40 seconds with a six minute surface interval between each. Sydney project team leader Samir Alfathi said the divers were astounded by Sachaâs achievement. âIt was amazing to see her do this, and my impression was how easy she made it look,â he said.
âI really didnât expect her to be able to spend as much time on the bottom as she did,â added Dave Apperley. âMost (people) would think there would be a time limit to these types of dives (but) it certainly didnât appear that way. Everything is so methodical and slow motion with Sacha, you start to wonder when sheâs going to go up.â Sacha even freedived again to open a celebratory bottle of champagne with the scuba divers while they were decompressing.
âTo be honest,â Sacha said. âThat this dive seemed so impossible is perhaps a sorry indication of just how far removed from our environment weâve become, or how weâve lost touch with what the human body is capable of. Mentally, it is a very difficult thing to challenge our strongest survival instinct – to breathe – but we are capable of so much more than we realize, or remember.â
The Sydney Project team has since set Sacha another challenge â to freedive and explore a wreck at around 75m.