Technically Speaking: The Limits

How deep can you dive? It’s the most common question a wreck diver gets asked by non-divers; and the answer is usually not that straightforward. Dive limits are not only physical to the diver in terms of the human body or the equipment used. But it’s also the factors in a divers surroundings that affect these limits.

Tech diving has advanced so much in recent years, that we are able to explore places never before possible. But this advancement doesn’t stop, it will always continue if only slowly, it still moves ahead.

There are vast amounts of ocean we want to explore but we are limited by lack of specialised equipment and affected by environmental factors beyond our control.

Wreck divers in Australia are finding that newer wrecks are more than likely in deeper waters. Very rarely these days we are finding new wrecks in waters accessible within recreation limits i.e. within 30 – 40m. This presents a host of challenges which are being tackled by various groups of tech divers such as Sydney Project; the reward though – virgin wrecks.

Two new wrecks sites are known to exist. Sydney Project has untaken a handful of initial search days in an attempt to eliminate / confirm possible marks. The sites the team is scanning are now on the edge of the limits in terms of depth near the continental shelf. These wrecks are lying in waters as deep as 160 metres, and in an extreme current zone, currents which may run at over 4 knots, and which can appear anywhere in the water column at a moments notice. This is every diver’s worst nightmare to face such a current somewhere mid-water on a very deep dive.

Other dangers to a diver diving this far offshore, 20 nautical miles, is the long way to get back quickly in an emergency. The dangers are not limited to decompression issues only. The open sea poses dangerous marine life to be aware of. This is the domain of all pelagic fish, with sharks a real hazard for divers hanging for 6 hours of decompression.

But before we can even start tackling the logistics of undertaking such a dive, in a site such as this, we need to find a way to get there. This may sound like an easy task, but it’s proving to be anything but easy.

Charter operators for fishing and diving have limits to how far a vessel can go offshore. There is also the limit of a skipper’s license, which may only be licensed to go a certain distance out to sea. The list of available operators quickly narrows down to a select few, and usually are pure fishing charters. Now we have two tasks, convincing this operator to take a group of divers so far offshore, and wait for 7 hours to do their dive. The second is finding a free date from their fishing trips to take the boat out to sea.

But wait, there are more. Since the government introduced the buy back scheme for fishing licences in NSW, we had a dramatic reduction of trawlers and fishing charters. This means that as divers we not only loose a valuable source of information from the fishermen about wreck sites, but also our choice of available vessels for offshore diving that are licensed to go there.

For Sydney Project, it’s been a frustrating wait of over 5 months now to find suitable vessels, and only now there have been positive developments.

The diving limit for divers in the water is always a major issue. Equipment is one major factor; the rate at which we are gaining knowledge of diving in deeper waters is much quicker than the technology currently available, and divers are often take the matter in their own hands to invent and build, the tools to get them to the point of exploration. This is more evident in cave diving where the sidemount rebreather was created. This opened a host of new opportunities to explore new cave passages, with much smaller teams in much more difficult and remote locations. This is something that was not possible in the past with open circuit. Now the biggest issue for cave divers and in particularly in NSW, is to break through the ancient bureaucracy in places like Jenolan Caves, where rebreathers are still banned, even though their use has been proven in other cave regions and on shipwrecks.

In ocean diving on wrecks in deeper waters, it tests not only the diver doing the dive, but also all the equipment that are being used, and divers despite what anyone would say always push their gear to the limit.

 Everything we use has a limit of operation, and most of the time divers will break these limits. Rebreathers all have limits, this may be physical components, or it may be physical mechanics of scrubbers and loops. There are too many factors to consider when thinking of rebreather limits, but any divers doing serious dives on modern rebreathers would be going beyond their limits. This of course needs to be taken in context of the operation. What may sound like a dangerous exercise in doing so, most of the time it’s probably safe to do, if done the right way. The limits are there for a reason though and they need to be understood before pushing them.

These limits are not only restricted to rebreathers and other dive equipment, its also applicable to Audio Visual equipment. Most housing for still and video cameras have limits, which again are broken by majority of deep divers. An insurance policy may be a good idea before doing this! This equipment is sensitive pieces of hardware, and combines many components that all have limits. Lenses, monitors, housing body, lights and other pieces, are all subjected to depth limit, and it’s critical to know just how far you can push it.

Most important piece of equipment is the divers themselves, to undertake such deep dives is another step into the unknowns. A person who is thinking of doing such a dives need not only be physically ready, but also be mentally ready. This means being honest with themselves and their buddies about their comfort levels, and overall feelings of undertaking such a dive. This is the time when every bit of ego and pride should be thrown away, and serious thoughts must be put into this decision.

In general life we have laws, rules and limits that we are bound by, some are there for your safety and to make life organised, and some just don’t make sense and frustrating. Still we obey by these rules legally and morally. But in diving we often ignore rules and limits put on us, and again some are there that are a must, and some just should not exist, but still those rules and limits that are important and should be obeyed, are more easily violated by divers. Tech divers are by far the worst offenders, but having said this, there is times and places when rules and limits just don’t exist, and are set by those that push the unknown, there are no limits in exploration.


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