Michael McFadyen's Scuba Diving - Inquest, Himma Deaths
On Monday 11 May 1992 the Coroner's Inquest into the deaths of two divers was held at the Glebe Coroner's Court, Sydney. The divers, Richard Alistair YARROW, 31, and Bradley David SMITH, 33, died on Monday, 7 October 1991 (the October long weekend) on the wreck of the 34 metre long tug Himma off Narrabeen, Sydney. The Inquest was held before Mr Derrick Hand, New South Wales Deputy State Coroner, with Sergeant John White assisting.
Evidence was presented by the investigating officer, Senior Constable Glenn Finniss, as well as a number of the persons involved in the diving that day and the subsequent search. It was shown that Smith and Yarrow were experienced divers, holding Divemaster, Deep and Wreck Diver certificates. Their training had included diving in nil visibility conditions. They had done numerous deep dives and had dived on the Himma about four times. They were regular buddies and two days earlier they had done a dive to 44 metres. However, no evidence was produced to show the exact numbers of deep dives or even total dives they had done.
The evidence shows that at about 9.30 am on the day in question, Smith and Yarrow joined a dive trip run by Herb Adams on his 7.1 metre charter vessel, Venturer, to dive the Himma, which lies at about 50 to 52 metres off Long Reef. The weather conditions were said to be very good for diving, with a north east breeze at 10 to 15 knots, slight seas and "a current from the north of 2 knots". As no mention was made of assistance being provided to swim to the front of the boat, it is reasonable to assume that the current was far less than was stated, as it is impossible to swim against a 2 knot current for more than a few metres. It is more likely that the current was in the order of half a knot at the most. This is not really relevant to what happened, but it does show the shortcomings in the investigation and the facts subsequently presented to the Coroner.
The Venturer arrived at the Himma and the other two divers on the trip, Phil Coony and Simon Hunter, started their dive at 9.55 am. Before Smith and Yarrow entered the water another dive vessel, with four divers, came alongside and tied up to the rear of Venturer. At 10.04 am Smith and Yarrow started their dive and at 10.12 the four divers from the second boat, David Willows, Richard Bradley, David Kinder and David Masters began their dive.
Coony and Hunter secured the anchor and then went into at least one of the tug's holds and then through the hole that sunk the tug to the outside and forward to the bridge. Visibility was 8 metres, which was confirmed by all divers. They then went through the bridge area to the entrance to the compartment where Smith and Yarrow were eventually found. This compartment was the crew's accommodation area and is below the main deck. The entrance is about 0.6 metres square and there is a raised coaming about one metre high around three sides. A ladder extends from the fourth side. This side is about 0.5 metres off the rear wall. Coony dropped into the entrance, looked around, and then exited. He had decided that it was not safe to further examine the area. He stated that visibility was about 6 metres in the compartment. It might be noted that Coony is an Instructor and a certified Cave Diver. His buddy, Hunter, put his head into the hole and then left. Hunter also stated that Coony's fins and legs were covered in a heavy layer of silt after even this short examination and that the silt was slightly disturbed.
They then swam to the rear of the tug and examined the props. It would appear that at this time Smith and Yarrow reached the bottom and swam straight to the bridge area as Coony and Hunter never saw them during the dive. After seeing the props they returned to the anchor and as 19 minutes had elapsed, they ascended.
The four divers from the second boat passed Coony and Hunter at the 30 to 38 metre level. Adams on the dive boat saw by their (Coony and Hunter) bubbles that they were ascending at 10.15 am. The four divers went through the holds and then to the upper levels of the bridge. By this time it was about 10.17 am and Smith and Yarrow had been down 13 minutes. I believe that their air supply was almost exhausted by this time (as I will explain later). At no time did they see Smith and Yarrow or even go to the level of the entrance to the compartment. David Kinder later stated that he thought he saw bubbles coming from the foredeck area. This would tend to confirm that Smith and Yarrow were already in the compartment and (presumably) already lost inside but possibly still alive. The four divers then returned to the anchor.
After 11 minutes two of the divers ascended and the other two went to the stern of the Himma. It was now 10.23 am. They soon returned to the anchor and at 15 minutes (10.27), they too ascended. By this time Smith and Yarrow had been down 23 minutes, 3 minutes more than their dive plan. As I will show later, I believe that they were already dead.
While this was going on, Coony and Hunter were decompressing and wondering where Smith and Yarrow were. They came to the conclusion (hope) that Smith and Yarrow had aborted the dive early and were on board the Venturer.
At about 10.40 am the four divers from the second vessel surfaced and at 10.55 Coony and Hunter surfaced. Immediately questions were asked by Adams, Coony and Hunter as to the whereabouts of the missing divers. All six divers reported that they had not seen them during the dive.
It was assumed, not unreasonably, that they could not find their way back to the anchor and were doing blue-water deco in the current. Both dive boats began searching the area to the south of the Himma. It was calculated that Smith and Yarrow would surface at 11.10 am if they stuck to the dive plan and did additional decompression to compensate for inaccuracies in maintaining the correct depth during this deco.
After a fruitless search, Adams telephoned the Westpac Rescue Helicopter Service at Prince Henry Hospital at 11.27 am. He had returned to the wreck and was again anchored on it. The other vessel continued searching until it was low on fuel. At 11.45 Senior Constable Finniss at Broken Bay Water Police was notified by Westpac of the situation. He headed to the site immediately.
At 11.55 the Westpac helicopter arrived and began a search. It was soon joined by Polair 3 and shortly after by three television helicopters. A number of vessels also assisted.
At 2 pm the Police divers arrived and dived on the wreck. Constable Neil Morris was the first diver on the wreck and his team searched the outside. He then did an extended search around the wreck as it was still believed that divers were not on the wreck. Another team of divers examined the wreck itself (supposedly including the compartment) but found nothing. The Police diving operations were halted due to oncoming darkness.
Paul Rosman and Stewart Bell from Deep 6 Diving Manly, who had arrived on the scene earlier, then did a dive and went straight to the compartment. They found silt coming out of the entrance and decided that it was not safe to enter. They searched the wreck and surrounds.
The next morning, Rosman and Bell again dived the Himma and found that the entrance was still silted. They did a very limited search of the area near the entrance before again deciding that it was too dangerous. Another check was made of the wreck and the sand out to 30 metres.
Rosman and Bell decided to wait until the Thursday to let the silt settle. The story of the actual search on that day was related by Rosman in the December 1991 issue of DIVE Log so I will not repeat it here in detail. It is sufficient to say that Bell found one diver, Yarrow, in the compartment and he was removed with a great deal of difficulty. All his equipment was in place except his mask (which was not found) and his regulator was not in his mouth. The Police were informed and a few hours later Smith was located and brought to the surface by Const. Morris. Morris testified that he had a great deal of trouble bringing the body out and in the silt could see nothing, repeatedly hitting his head and body on a number of stanchions in the compartment. Unlike Yarrow, Smith's BCD and tanks were not on his body but all the rest of his gear was in place.
Bell had reputedly stated to Police that he had seen Smith lying face down in the silt with his yellow tanks visible. Morris stated that he found the body face up in the silt without the BCD attached. The next day he retrieved the BCD and tanks (which were blue in colour, not yellow) from the roof of the compartment where they were floating due to the fully inflated BCD. No questions were raised concerning this contradiction. Apart from blood oozing from the eyes, ears and mouth of Yarrow, there were no injuries to either body. There were no injuries to either person's hands. This completely dispels the rumour that was circulating, at least in the Sydney dive community, about the condition of one or both divers' fingers. It proves that people should never believe rumours.
The inquest was terminated at this point by the Coroner who had obviously decided that he had heard enough details. The later witnesses, including Rosman and Bell, were not called.
A post mortem examination showed that Yarrow had died from "the effects of hypoxia [low oxygen level] due to oxygen depletion in the scubadiving gear he was wearing" and Smith from "the effects of lack of oxygen". Neither died from drowning. It is possible that Yarrow was breathing so rapidly (and shallow) that he was not getting enough oxygen and he fell unconscious before running out of air. It is probable that Smith was not as panicked and he did not pass out until the moment before he died.
The following details were ascertained from the investigating officer's report to the Coroner. Both Smith and Yarrow were using a twin tank set-up, with two 63 cubic foot tanks and independent regulators. It might be noted that the equipment was top of the range gear but that both Yarrow's tanks were some months out of test.
Of the four tanks used by Smith and Yarrow, all were empty but there was enough air in three of the tanks for air purity tests to be done. The composition of the air was okay with normal oxygen, nitrogen and carbon dioxide levels. There was no trace of carbon monoxide. The Police then tested Smith and Yarrow's regulators and found that apart from a very minor leak in one reg used by each man, the equipment was in good order. They then took the BCDs, regs and tanks and dived to over 30 metres. No problems were found with the equipment. It is therefore certain that it was not equipment problems that caused the accident.
A big thing was made at the inquest of the fact that both were wearing reels. This statement was repeated many times by the other divers, the Police and Adams. However, this was not true. The Police records show that Smith had a 4 metre length of folded florescent green line in his BCD pocket and Yarrow had a 9 metre length of folded orange safety line with snap shackles at both ends in his pocket. No other lines or reels were carried.
Other mention was made of the effects of nitrogen narcosis at that depth, but it was limited to asking each of the divers involved whether they were affected on the dive. No expert opinion was given nor medical advice submitted on the possibility that nitrogen narcosis caused or contributed to the accident or even what its general effect would be at that depth.
Before proceeding further, I will give a brief description of the compartment in question. The area was immediately below the bridge and below the deck. It is accessed through a hatchway about 0.6 m square. No direct light shines through the hatch. The compartment itself is trapezoid in shape, about 6 metres long, 4 metres wide and 2 metres high. It is narrower at the far (bow) end than where the entrance is located. The compartment was formerly made up of a number of smaller rooms but the internal walls have been removed. A number of stanchions remain along each side running parallel to the hull. These are spaced such that a diver can easily fit between them. According to Const. Morris, a number of additional stanchions are located near the forward bulkhead, about 1 metre off the wall and spaced only 0.4 metre apart, far too small for a diver wearing twin tanks to fit through. However, Paul Rosman does not believe that they exist and has video evidence to support this. There is some electrical wiring and rotting material hanging down from the roof and the floor is covered in a thick layer of silt.
Evidence and accounts from witnesses (generally accepted by the Coroner) suggest that the following probably occurred.
Smith and Yarrow reached the wreck while Coony and Hunter were examining the prop. They went directly to the bridge and then entered the compartment entrance one at a time. Possibly impaired by nitrogen narcosis, the scene that confronted them appeared safe and visibility was okay so they did not use their safety lines. The first diver probably moved into the compartment a bit further and the other followed. They then went in further, not knowing that they were disturbing the silt. After going in a reasonable distance, they probably turned around and were confronted with a scene of complete blackout similar to that encountered by Const. Moore when recovering Smith's body.
They probably became apprehensive and started searching for the exit. Unfortunately, even if they followed the join of the roof and the wall, they would not have found the way out as the entrance to the compartment is almost half a metre off the wall and unless they remembered this, they would have passed straight by the only way to safety. The worsened visibility and the apprehension would have markedly increased the effects of nitrogen narcosis. They obviously did not totally panic as they swapped their regulators at least once to use the air in the second tank. Their efforts to find a way out would have compounded the poor visibility.
Somehow, Smith became "trapped" behind the stanchions in the bow (assuming that they exist) and thought that he could not get out so in a last attempt he removed his tanks and pushed them through the space and then ran out of air and died. Yarrow was probably unconscious with hypoxia and ran out of air soon after. I have calculated that assuming it took Smith and Yarrow 2 minutes to reach the Himma, 2 more to get to the bridge area and another 2 minutes to enter the compartment, they would have used 21% of their air supply if they had a Respiratory Minute Volume (RMV) of 15 litres/minute. If they then panicked and started breathing at a rate of 60 litres/minute, which is the rate of a very fast swim and certainly possible under the circumstances, they would have emptied both tanks in about 5.5 minutes. Therefore, by 11.5 minutes into the dive (10.16 am), Smith and Yarrow could have been dead. This is one minute before the four divers got to the bridge area.
What was the Coroner's official finding? No blame was attached to any person, including the dive boat operator, Herb Adams, or the other divers. He found that Smith and Yarrow were properly trained and equipped. The only written finding was the actual cause of death as described in quotation marks above. However, the Coroner did make a number of comments at the end of the inquest. I have paraphrased his comments below:
Unfortunately there were a number of deficiencies in the inquest as far as I was concerned. These include the fact that the other divers were treated as experts and asked questions relating to training, narcosis and standards that should have been directed to persons such as a diving physician, a deep diving instructor of renown etc. Also, the fact was not really made that Smith and Yarrow were not carrying reels. The adequacy of training for deep dives was not addressed sufficiently and I know that Paul Rosman and Stewart Bell were disappointed not to be able to put their point of view on this matter.
I would have expected that the Coroner would have wanted to know more detail about Smith and Yarrow's certifications and training, the record of their dive log books and the adequacy of the certification agencies relating to this sort of diving. No real evidence was presented on this matter.
Finally, what can all divers learn from this tragic accident?
NOTE: I later wrote a follow up article taking into account recent dives on the Himma. You can read this article by clicking on this URL. An article on the Himma can be read as well.