Michael McFadyen's Scuba Diving - Blue Water Ascent
The wreck of the SS Catterthun is located about four kilometres off Seal Rocks on the lower Mid-North Coast of New South Wales. The wreck is one of the best in Australia, although its depth (55 to 60 metres) and the difficulty in getting a dive boat to take you there (a lack of launching ramps at Seal Rocks for example) means that very few people get to dive it.
Over the weekend of 27 to 28 May 1995, I travelled to Seal Rocks to dive the Catterthun with a group of divers from Sydney. On Saturday 27 May 1995, we had an awesome introduction to the wreck, with 25 to 30 metre visibility. My dive was made more exciting by the sighting of three or four bronze whaler sharks while doing about an hour's decompression (we did about a 20 minute bottom time). Two divers had an even more exciting dive when about 30 bronze whalers turned up towards the end of their decompression. They became so worried that they actually cut short their deco by a couple of minutes, satisfied that what they had already done met the requirements of most decompression tables.
The next day saw us out at the wreck again. I was buddying with Rick Latimer, one of Australia's most experienced and knowledgeable wreck divers (Rick has since passed away). There were two other divers on our boat and a driver. We had another boat with four divers and a driver. Two of these divers were Scott Leimroth and, I think, John Szwecow. All divers were using twin tanks (88cf or larger) and were all experienced deep divers. On our boat the first two divers entered the water and then Rick and I geared up. We followed, probably about 10 or so minutes behind them. On the other boat, a similar procedure was followed with Scott and John entering the water second.
Conditions were perfect on the surface - calm seas (better than the day before) and a very slight current from the north-west. The wind was fairly strong from the west. Anyway, once we entered the water we noticed a dramatic change from the day before! The water on Sunday 28 May 1995 was dirty, with visibility now only five to seven metres. Our anchor was towards the stern of the wreck, on the eastern side and only a metre or so from the sand (which surrounds the wreck on all sides). I motioned to Rick that I wanted to tie the anchor up better than it was presently but he indicated not to do it. I deferred to his greater experience.
For the next 12 minutes we had a look at the stern area of the wreck as the previous day we had visited the middle to bow section. Towards the 12 minute mark we stopped moving much and explored in detail one small area near the sand on the eastern side. Rick was intent on removing a colourful coffee mug from where it was cemented into the wreck. During this period I checked on the anchor a couple of times and found it in its location. By now, the other divers on our boat had ascended as had the first pair on the other boat.
At about 18 minutes I noticed Scott and John descending from about 10 metres above me and waving wildly. They came towards me and within a few seconds I figured out that they had lost their anchor. I signalled to them okay and not to worry as our anchor was close by. I led them towards our anchor but guess what? It was missing. All I could see was a line in the sand where the anchor and chain had departed. I quickly followed it but nothing was to be seen. I signalled to the others to start ascending slightly towards Rick who was still on the wreck.
I dropped down to Rick and told him we had to leave right now. He waved me away, telling me we still had a minute or two before we needed to ascend. I grabbed him and indicated that the anchor was gone, he understood and in his haste, he broke the coffee cup. We had now been down for just under 20 minutes and our total decompression time using Aladin dive computers was 56 minutes as follows: 3 minutes @ 12 metres, 6 @ 9 m, 15 @ 6m and a massive 32 @ 3 metres. We started up, taking five minutes to reach 12 metres. As I indicated earlier, there was a slight current from the north-west so we swam towards the current as we did our decompression.
One of the problems was that since the two boats each had two divers under them doing their decompression, they could not move off to search for us until their divers had completed their deco, assuming that they knew that we were not under the boat. This would be almost an hour from now.
Unfortunately, only one of us had a safety sausage (Rick I think), but it only had a line of about three metres or so. Therefore we could not use it till we got to the three metre mark. The decompression was a long, long time, especially when my thoughts kept going to yesterday when Scott and his (different) buddy had been hassled by dozens of sharks. I thought "Hell, I hope they do not turn up today".
Everything went fine and at three metres I put the safety sausage up. This was quite a difficult task, as the short length of the line meant that I had to be right at three metres and even then, the buoyant sausage kept pulling me up and I did most of the next 35 minutes upside down.
After about 65 minutes, Rick got low on air due to constant swimming into the current so he used one of my regs attached to the tank I was not using. This made it more difficult for me. Finally, after we had been down 75 minutes, we heard an outboard motor and we were quite relieved to see our boat pull up over our heads. I let go the sausage and after 81 minutes, came to the surface. I was feeling very sick due to spending the past 35 or so minutes upside down and being buffeted by the wind's effect on the sausage. I almost threw up as I surfaced but within a few minutes I was okay.
The amazing thing that we discovered was that the other boat was less than 20 metres from us, still anchored on the wreck. It appears that its anchor had moved down the wreck but did not come right off it. If only we had known this! In addition, we also found out that at one time during the deco, the two divers under the boat had seen colours off in the distance. That was us.
Well, what can be learned from this incident? Firstly, always make sure that the anchor is properly secured, no matter what the conditions are like. Secondly, make sure that you carry a safety sausage with a considerable length of line (at least 15 metres or more) so you can send the sausage up as soon as possible. Thirdly, swim into the current to make sure that you stay in the rough position of the wreck/dive site making it easier for you to be found. Fourthly, stay together as a group, especially in case one runs low on air. Finally, do not panic. So long as you have an intelligent boat driver, you should be able to be found quickly.