Michael McFadyen's Scuba Diving Web Site
Home Contact Me Sydney Reef Dive Sites Sydney Shipwrecks NSW Dive Sites Australian Dive Sites Overseas Dive Sites Dive Accidents and Incidents My Yachting Adventures 4WD Trips Weather Search 16 June 2024 06:31

About Me
My Diving
Web Links - Dive Clubs
St George Scuba Club
Some of my Best Photos
Contact Me

Dive Sites
Sydney Reef Dive Sites
Sydney Shipwrecks
Sydney Dive Visibility, Swell and Temps
Kelly Talking on ABC Sydney about Shipwrecks
NSW Dive Sites
Sydney Shipwreck Summary
NSW Shipwreck GPS/Marks
Australian Dive Sites
Overseas Dive Sites
Aircraft I have Dived
Old Bottles
Free Shipwreck Books

Dive Related Equipment
Shearwater Predator and Heinrichs Weikamp OSTC 2N
Uwatec Aladin Dive Computers
Apollo AV1 Underwater Scooter
Bauer Compressor
DIY Oxygen Stick - Nitrox
GoPro HD Hero Video Camera
My Camera Setup
Purchase of New Dive Boat
My Dive Boat - Mak Cat
My Old Dive Boat - Le Scat
My Dive Gear
GPS and Diving
Make Your Own Car Tank Rack

Marine Life
Rarer Sydney Marine Life
Bare Island Pygmy Pipe Horses
Bare Island Sea Horses
Bare Island Nudibranchs
Bare Island Marine Life
Encounter with Southern Right Whale and Calf

Other Dive Info
How Weather Affects Diving in Sydney
Visibility and Wave Averages in Sydney
Waves and Diving
Diving Weather and Sea Conditions
Tide Tables
Dive Accidents and Incidents
Dive Book Reviews
Site Map
Noel Hitchins 1951-2005
Lloyd Bridges - Mike Nelson in Sea Hunt
My Yachting Adventures
Below is a list of links to the main pages about my yacht, Catlypso and My Yachting Adventures:
  • Purchase of Catlypso
  • Details about Catlypso
  • Cleaning/Repairing Catlypso
  • My Yachting Adventures.
  • Login


    Forgotten your password?
    Request a new one here.
    Michael's 4WD Trips
    Click here for a list of my Four Wheel Drive and Camping Trips.
    Home Brewing
    Click here for an article about Home Brewing.
    Sydney Dive Site Hints
    "Osborne Shoals West has excellent fishlife and sponge life"
    Severe Dizziness - Thought to be DCS at First
    Michael McFadyen's Scuba Diving - Severe Dizziness in a Male On Sunday 17 May 1998 I drove down to Jervis Bay from Sydney with a regular dive buddy. We were originally going to dive the Sir John Young Banks off Shoalhaven Heads, Nowra, after a call the previous night from a friend who lives near Jervis Bay. The seas had been absolutely flat on the Saturday which would have made diving the Banks possible (flat seas are essential as the site is 22 kilometres off the coast). The weather was obviously not as good as we drove down and a check at the top of Bulli Pass before we descended into Wollongong confirmed this fact. The seas did not look too bad, but the Banks was certainly out of the question. A quick call to the friend in Jervis Bay confirmed our view but he decided that it should be possible to dive somewhere good. We continued on our way.

    After arriving at the friend's place we loaded all our equipment on board the 17.5 foot long fibreglass boat and then set off to the boat launching ramp at Murrays Beach on the southern side of Jervis Bay. We set out for the open sea, having decided to dive a site called Crocodile Head Gorge which is about four kilometres north of the northern headland. This is a reef that starts at 30 metres and drops in a couple of steps to about 50 metres.

    The seas were a bit choppy, perhaps half to three-quarters of a metre chop on a one metre swell, all from the south-east. The trip up to the dive site was not too bad, I have certainly been out in far worse seas. The water temperature was 17°C and the air temperature 18°C.

    We arrived at the dive site at about 1110 and we motored around for a bit as the boat owner showed me the marks for finding the site. We anchored first go and set up the decompression lines, cross-over lines and other bits and pieces. At first we thought there was a strong current from the north but after watching we noticed that the current was virtually non-existent. The wind was from the south-east, quite strong and the choppy seas made it not an easy job to put on your gear but it was not too bad.

    The four divers (including myself) were all male, all around 40 years old, all very experienced divers, very experienced deep divers and people I have dived with either hundreds of times or many times, depending on the person. The boat owner would be one of the most experienced divers currently diving out of Jervis Bay, with probably 1000 dives at Jervis Bay alone. Equipment was twin tanks for the three other divers while I had an 88 cubic foot main tank and a pony bottle as back up.

    My buddy and I entered the water first. I was confident enough of the water conditions to take my video camera and two lights (I never take it in any sort of current due to the extra drag it causes). We descended at 1132 and about a minute later hit the reef top at 30 metres. I waited for my buddy and then dropped over to the 35 and then 40 metre ledges before hitting the bottom at 49 metres about 2.5 minutes into the dive. After setting up my camera (adjusting lights etc) we headed off out of the gorge to deeper water where there are a few huge rocks. The depth here was almost 53 metres and the visibility very good, over 20 metres.

    After six minutes I headed back up the gorge and the depth came back up to 49 metres. As I did, I saw the other two divers dropping over the 35 metre ledge (so they were about six minutes behind us). I videoed them as they came down to the bottom. They then proceeded in much the same direction we had at the start of the dive but they did not get as deep, not reaching 51 metres. We were now in deco.

    We then continued to the end of the gorge before coming back along the opposite wall to the anchor. As we did, the other divers went up the gorge. After I videoed some black reef leatherjackets in this area I decided to start ascending up the wall. At 14 minutes we left the bottom of the wall and zig-zagged up the wall eventually reaching the top of the reef where the anchor was resting on the edge. While doing this the other divers passed right under me at the bottom of the wall as they came back to the anchor area.

    At 17 minutes we left the bottom and my decompression at this time according to my Aladin Air-X was 1 minute at 9 metres, 4 minutes at 6 metres and 15 minutes at 3 metres but in reality turned out to be 3.5 minutes at 6 metres and just over 14 minutes at 3 metres (this is from the download of my computer).

    Before I reached the first stop the nine metre stop disappeared and at 22 minutes I reached the six metre level (that is it took five minutes to come up 24 metres and eight minutes to come up 43 metres - well within all recommend ascent rates). The other divers arrived at the deco stop at about the time we moved to the three metre deco stop, that is 26 minutes into my dive and about 20 minutes into their dive. When my remaining deco was 10 minutes, the other divers moved to the three metre level and I noticed that the computer of the boat owner said he had to do 11 minutes of decompression at that level. Therefore, the other divers had "caught" up two or three minutes on us. This would lead me to believe that they had not been as deep as long as we had.

    After finishing my decompression I spent an extra eight minutes at four or five metres. My buddy exited a minute or two before me, as he had cleared a minute or two before me. The time was now 1219. My buddy tied off his gear to a line and climbed aboard the boat. I passed him my camera and then pushed my BC and tanks up to him. I climbed aboard and helped pull his twin tanks onto the boat. Soon after the boat owner came to the surface and then he and my buddy pulled his tanks aboard. This meant that he had also done more than five minutes extra stop. A few minutes later the remaining diver (let's call him RD) ascended and I and my buddy pulled his tanks onto the boat. We then brought up the deco weights and other lines while RD climbed aboard. He had done about 10 minutes safety stop on top of his decompression.

    The anchor was then lifted using a buoy and RD pulled the rope into the boat assisted by the boat owner. The chain and anchor was pulled aboard by RD.

    We then travelled a bit further north to the protection of the Drum and Drumsticks and anchored in a calm and isolated cove where we started on our lunch. Before I go a bit further, a few details about RD. He is a 42 year old, a very experienced diver and deep diver, a few kilograms overweight but quite fit. The day before he had dived to 57m and this dive had a 22 hour surface interval. For dinner, he had consumed half a bottle of wine.

    Anyway, once we got to the cove RD informed us that he was dizzy. He then vomited badly over the side and the dizziness continued. We put him on oxygen but he was still dizzy and sick so we decided to take him ashore and we motored in as close as we could and my buddy assisted him ashore. We also put ashore a small cylinder of oxygen and he continued breathing it. He vomited again and wanted water. We made him comfortable (he was lying on rocks, all the flat land was small rocks) by placing a wetsuit under his head, gave him water and covered him with another wetsuit to protect him from the cold (it was the start of winter and a cool day).

    After 20 minutes he had not got any better so we decided to call for assistance. By this time I was also ashore and the boat owner called the Coast Guard. They then put into action a plan to get the police boat from Huskisson to us together with an ambulance officer. After a bit of thinking, I figured that it was going to take at least 90 minutes for the boat to get to us so I asked the boat owner to get the resuce helicopter from Wollongong or Sydney down to us. This he did via the Coast Guard.

    We continued to treat RD using oxygen. He was not responding and was feeling tired (sleepy) and still dizzy when he attempted to sit up. He started shivering, but whether this was from shock or the cold it is hard to say. We did some checks. He had no pain, no tingles, no lack of movement and was fully coherent. We ran out of oxygen in the small cylinder so I transported to the shore my larger oxygen tank. We kept him on oxygen (with small breaks) for over an hour. When he went off oxygen, he did not get worse.

    At 1425 the Westpac Rescue Helicopter arrived from Sydney. We had been out of the water about two hours and it was about 85 minutes since we called for help (about 65 since we asked for the helicopter). The Police launch arrived a few minutes later. It was so big it could not have got close to the shore.

    The helicopter winched down a doctor and medic (this was Paul Featherstone - he had rescued Stuart Diver from the Thredbo landslide 9 months earlier) as well as equipment. They kept RD on oxygen and put a drip on him. After checking him out, they decided to evacuate him to Sydney and after about an hour, the chopper winched the three back up and departed for HMAS Penguin. We gathered our gear together and headed back to Jervis Bay.

    After arriving at Penguin, RD was assessed and then received his first treatment. He was no better, still very dizzy with a headache but could walk. The next day a second treatment again had him no better but he could walk a bit easier. A few hours later his dizziness subsided. A few more treatments made no difference so he discharged himself.

    RD then went to his doctor and was prescribed Stimotol and within 48 hours his dizziness disappeared completely.

    What happened? Well, after I suffered an almost identical occurrence about five months later, I believe that the following is probably what happened. The ear is, of course, the most important organ in relation to balance. A problem with your ear can cause extreme dizziness. All dive medicine books I have state that a burst ear drum (or for that matter, any ear problem) occurs in the water. This did not occur here nor did it in my problem.

    My guess is that RD suffered an inner ear problem, probably a burst round window (which is between the inner ear and the middle ear). This is called a fistula of the round window. What happens is that the inner ear fluid leaks into the middle ear, this causes dizziness and some other symptoms. As to what causes this, I have been given different suggestions by a number of doctors. The first is that there may have been an ear infection that caused the Eustachian tube to close and when ascending, the air in the middle ear expanded and, not being able to escape out the tube, burst the round window. This also assumes that there is some inherent weakness in the round window. The second is that RD had a specific ear problem on the day in question and pushed his ear past its limits.

    Whatever it is, it was not nice for RD and it was not nice for us. Also see the article about my problem.

    I have learnt that RD suffered a similar incident again in mid-1999. He did not recover his complete sense of balance and even 10 weeks later was still extremely dizzy. He then underwent surgery and regained 90% of his balance. This was in December 1999. I spoke to him again in 2008 and he has basically fully recovered. When they operated, they found scar tissure from the previous damage, confirming my suspicisions as outlined above.


  • Deeper into Diving by John Lippmann
  • Diving and Subaquatic Medicine (3rd Edition) by Carl Edmonds, Christopher Lowry and John Pennefather

  • Copyright © Michael McFadyen 1990 to 2024
    Non-commercial use of an article or photograph is permitted with appropriate URL reference to this site.
    Dive shops, dive operators, publications and government departments cannot use anything without first seeking and receiving approval from Michael McFadyen.
    This web site has been wholly thought up, designed, constructed and funded for almost 30 years by Michael McFadyen without any help from the Australian Dive Industry.
    Website created 1996!