Hévíz, 42m cave dive, Hungary January 29, 2006

Following Cousteau

Introduction

After several months lacking real dive made my quills dry. The shower at home and the swimming pool kept me alive, but I was really longing for a real dive adventure. Though Hungary does not have warm sea (as a matter of fact, Hungary does not have sea at all) we do have a warm lake: Hévíz.

I planned this dive to happen in January on a Sunday. (My Saturdays are occupied by MBA studies.) A few weeks ago Attila Rajky was calling me, who I knew from lake Dorog that they were preparing a trip to the lake at Hévíz. I jumped on the wagon.

Hévíz lake is a warm one. The water comes from a cave at the bottom of the lake at depth around 40m and it is 38oC. The temperature of the water at the top depends on the volume of the source and the outside temperature. It is said to be never lower than 23oC. The day we dove it was 22oC. Diving in the lake is not free. You have to accept the terms of the local dive center, which is entitled to arrange and manage the dives by local authorities. You have to pay and last but not least, you have to wait to get a free slot. The number of dives is limited and there are many prospects wanting to dive.

The reason for this is twofold. On one hand the lake is a reserve to be saved. On the other hand diving there can really be dangerous if performed by inexperienced. In this case experience also means knowledge of the local specialties. Jacques Cousteau was also "inexperienced" when he dove there many years ago. He and his group followed their own decompression routine, which was less than effective resulting decompression pains in their joins.

There is no documentary evidence on that though; it is word of mouth. However there are photographs on the walls of the dive center showing Cousteau and company using 10L tanks and no BCD. These days nobody dives the cave with a tank smaller than 15L.

Diving in this lake is again: special. This is because of

  • depth,
  • cave,
  • warmth,
  • decompression.
Nitrogen saturation happens in a warm water at 38.5oC, while decompression in the relatively lower temperature at 27oC. Because of this the decompression should be performed following a scheme, which is more rigorous than the most dive computer calculated scheme. This case we planned to spend 20mins at the bottom at 42m and it required 15m/1min, 12m/1min, 9m/5min, 6m/10min, 3m/20min decompression. This was calculated and practiced during the last few thousand dives performed in the lake.

On the picture left you can see the cross-section of the lake (I borrowed the picture from Poseidon Diver Corp from their web site). This cross-section shows the path we descended in the lake. We started from the surface following the tubes leading the hot water from the cave to the buildings. There are also ropes helping the descending. At 9meter where the tube starts to be from 45o to vertical there is a platform to stop and exchange OK with each other before starting for real depth.

Preparation

We arrived at the DC at 9am. There was a short, but really detailed and important briefing. They told us how the lake looks like, depth, water temperature, horizontal and vertical map, ropes, decompression levels and times.

The DC is close to the lake, just on the other side of the road that did not have too much traffic this time of the year. We used a small trolley to transport all the tanks and other tools to the lake.

Dive

After the briefing we were arranged into five groups. I was in the first one with two of us only with a local DM (Bea). The other groups consisted of three divers plus the DM. The tree of us started to swim at the surface from the immersion point to the start of descent. This travel took approximately five minutes. The water depth in this path is between 1.5m and 2m. There are buildings on the lake for the swimmers connected with corridors. All these are standing on poles. The lower parts of these are wood (probably larch), and the upper part concrete. The funny thing is that the concrete is wider than the wood beneath. The main building is under reconstruction these days and we had to swim under it on our way to the starting point. During this travel we passed some flowers.

After we started our descent I was a bit too fast and I did not wait for my buddy. Stupid behavior, I know. Fortunately Bea grabbed me and shouted at me: “What are you doing? Your buddy is still there!” She is one of the divers, who can talk underwater and I could understand the words. I realized she was right and we continued our descending in standard way arm distance.

At the level 38m we slowly reached the entry of the cave. This part is already bending back and is hidden from any surface light. The planned procedure said that the DM enters first the cave. When she entered the only light we had disappeared. It became totally dark and before I could even think about to take my lamp from my pocket my buddy grabbed my hand and he was shaking. He was evidently in panic. I kept his hand strong to prevent him releasing mine and to grab something else, for example my air rube. Later already at the surface he told me that he interpreted my fingers pressing his palm encouraging and helped him to lessen his panic. I had no such idea though when it happened. I selfishly wanted only to avoid him grabbing any of my equipment. Nevertheless he calmed down in a very few seconds and I released his hand and reached for my packet to get the lamp.

The entry of the cave is covered by a metal door with a rectangular 80cm x 90cm hole in it. To swim in we had to release the last drop of air from the BCD and to grab the wood and slip on the belly in pulling us inside. The warm water is flowing in front in a stream that it is not possible to swim.

When we were inside we placed ourselves on the platform kneeling. We were strongly requested not to sit on the platform having legs and thus the fins hanging no to stir up the mood. According to the plan our DM first came to me to guide to the middle of the large hall. I had to inflate my jacket to buoyant. SO I did and wanted to start to swim, but the DM stopped me and instructed me to push more air into the jacket. I realized that I was not inflating my jacket. This being the 25th dive I had experience to inflate my jacket, though not at this depth. I needed much more air. On the other hand I realized that I was mentally slow, worryingly calm, not alerted by the huge amount of water above my head and the closed space. It was due to the nitrogen. I also realized that I was oriented and not sleepy at all.

A few days later I was talking to Klári (my former and planned/future dive trainer). She was asking me if I did sleep enough before. I did not. I was excited the day before so I could not sleep more than five hours. That is usually enough to work next day without feeling tired, though quality suffers. Sometimes, when I know there is a hard day coming I take some pills to sleep. However I would never ever do that before a diving day. Never ever.

After getting neutral we swam into the middle of the hall. Bea was swimming behind me and grabbing some part of my equipment strongly guiding me in the room. I did not resist against the strong hold and let her move her lamps showing me the walls and the water sources. I was simply floating and been turned by her around. I had my camera running and I was filming the wall. I had the feeling that I made a great film about the cave. Next day in front of the PC realized I that I made a film of 18 minutes of black nothing. There are approximately 6 seconds of flashing lights that show some pictures that I can recognize it was the cave wall.

After I returned to the platform I let all air from my BCD and my buddy was making his round with Bea. When Bea returned she signaled me to hand over the camera to make pictures of us. I handed the camera still running to her. She wanted to make some pictures but in no time we could “talk” the situation and she made a few seconds of film. This is the only visible film made in the cave. After she made this short film she handed the camera back which I forgot to strap on my wrist. (Do not worry too much, read on!)

Returning from the cave was the opposite order. My dive buddy left the cave first, then it was my turn and finally Bea left the cave. Getting through the 2m long “tube” was easier this time as the stream was drifting us. Not to get stuck was the only thing to care about. When I got out (still at 39m deep) I realized that my cam was not in my hand. I had no flash of memory when I had it dropped. I told Bea (using hands, I can not talk underwater just as she can) that my camera was missing. She was caring about that and turned back to seek that.

I was sorry for my camera, but it was not a deep feeling. I remember I was thinking that this was going to be the fate of my camera, sooner or later (I did write about it in some previous report). I was also thinking about the seeking not to be longer than 4 or just 3 minutes. We had very little time left before the ascending had to be started.

I was really lucky that I dropped the camera not in the tube but after it on a place where the ground was rocky rather than muddy and that the camera was switched on, LCD lighting. I could find it in 10 seconds. I showed it Bea and we started out ascending.

While ascending we were really slow, as it is needed after such a deep deco dive. We stopped for a short while at 15m, one minute at 12m and so on following the deco plan. The five and ten minutes stop at 9 and 6 meters respectively were not too long especially that we were swimming around in the lake. The twenty minutes at 3 meter on the other hands seemed to be endless. We were standing, half laying on the two tubes that come from the cave. My buddy was drawing a smiling face into the mud covering the tub.

After the deco was over we slowly raised up to the surface and swam to the immersion point. 30bars remained in the tank which means average 17.5l/min air consumption. Getting dry and dressing was really cold in the air.

Conclusion

This was really a dive worth for the buck. The price was high, approximately 60EUR including air plus rental costs, but I do not mind. For this price I could dive a very special place in an organized and safe manner. Bea was a responsible, and experienced DM, who really new the place. I would trust her any time to dive with.

Also there were a lot of other things learnt: