What is considered a deep dive and 26 tips for deep scuba diving
Deep diving isn’t for everyone but sometimes to see what you want, you have to go a bit deeper. But what is considered deep diving?
Deep diving for scuba divers is when you dive below 18-20 metres (60-66 feet), which is the depth that newly trained scuba divers can dive. Although in reality a truly deep dive is over 30-35 metres (100-115 feet), which is the depth at which the next level of scuba diver certification will allow you to dive. All diver training centres have training to allow you to dive even deeper, with PADI and SSI having specific training to dive to 40 metres (130 feet) and BSAC to become a Dive Leader and dive to 50 metres (164 feet).
What is considered to be a deep dive depends on the scuba diving centre you train with.
The definition of a deep dive is slightly different between the training organisations. An Ocean Diver with BSAC can dive to 20 metres (66 feet). Whereas the Open Water Diver with PADI and SSI can dive to 18 metres (60 feet).
Therefore, scuba diving deeper than 18-20 metres (60-66 feet) is considered to be a deep dive.
What are the common depths for people who are just learning to scuba dive?
The most common depths for people who are just learning to scuba dive depends on the point they are at in their training.
To start, all beginner scuba divers commence with their training in a swimming pool. After this initial training, newbie scuba divers are restricted to a depth of around 10 to 15 metres (32-50 feet) for their first one or two dives.
This is to help learner divers get used to diving and breathing from a demand valve or regulator underwater.
Once the dive teacher is happy with progress, the beginner scuba diver can go a bit deeper. With PADI and SSI an Open Water Diver can dive up to a depth of 18 metres (60 feet), but with BSAC the Ocean Diver can dive to a depth of 20 metres (66 feet).
It's important to understand from the outset that attaining deeper depths shouldn't be treated as a competition. It's not about how fast and deep you can go, but instead it's about building up your confidence and experience at increasingly deeper depths, but slowly and safely.
Deep diving is not always necessary to have a great dive, so deep is not always better. However, there are certain wrecks or sea life at depth that require deeper scuba dives.
What is deep diving?
Once scuba divers are comfortable diving at depths of up to 20 metres (66 feet) depending on the school they trained with, they can begin to increase their diving depth.
With all scuba diving centres, going deeper requires additional training and certification.
The various depths and levels after this grade for the different dive centres varies too. For example, an Advanced Adventurer for SSI can dive to 30 metres (98 feet). However, you can take their deep diving course and increase this to 40 metres (130 feet).
With PADI the next stage is an Advanced Open Water Diver who can dive to 30 metres (100 feet). Like SSI this is increased to 40 metres (130 feet) on their deep diving course.
Whereas for BSAC the next level is Sport Diver and for this level of scuba diver qualification the depth limit is 35 metres (115 feet). BSAC don't run a specific deep diving course, but instead you can train to the next level of Dive Leader and then dive to up to 50 metres (164 feet) once qualified.
After the above certifications, you can take further training and certification to become a technical scuba diver.
Technical scuba divers dive deeper than even 50 metres (164 feet), but to achieve this they use either mixed gases or rebreathers. Both of these require additional training.
Why would you want to dive deeper than 18-20 metres (60-66 feet)?
Deep diving is not about simply wanting to dive deeper, but is instead about how deep what you want to see is situated.
Many scuba divers love to wreck dive. The UK for example has more wrecks around its coast per mile of coast line than anywhere else in the world. Some of the great wrecks in the UK and around the world for that matter, Truk Lagoon comes to mind when I say that, are deep.
When I say deep, I mean more that 40 metres and many more than 50 metres.
To really experience a wreck at depth you need to consider decompression stop diving. As bottom time for deeper scuba dives is so limited on a no decompression stop dive, you don't get to see too much.
It's not just wrecks you see at depth
There are other reasons to dive deeper than 18-20 metres (60-66 feet). For example, there are some great dives in the Red Sea where you dive deeper to see and scuba dive with sharks.
Two great examples of this is the Elphinestone Reef and The Brothers in the Red Sea. On Elphinestone Reef there's a current that runs (but not always) north to south along the reef. The best dive is to be dropped off on the northern tip of the reef. Then dive straight down as soon as you hit the water (experienced divers only for this dive).
The dive is down to a coral plateau sitting at around 42 metres (138 feet). But with a bit of care and experienced diving, you can get to a part of the plateau at around 30 metres (100 feet) too.
If you manage to get to the plateau before being swept towards the reef itself, and then you're able to hold on to a rocky outcrop, you'll be blessed with the sights of sharks, which mostly include Hammerhead sharks and the Oceanic White Tip Sharks.
Deep diving comes with risks
The deeper you dive, the more risks are associated with the dive. This article Emergency decompression stop vs safety stop, I go into a bit more detail about deep diving and decompression stops.
However, in brief, all dives are decompression dives, as our bodies are subject to pressures that are much higher than we experience on land. This pressure has an effect on the air we breath at depth. It means that the nitrogen is dissolved into our body tissues and needs time to release from the tissues on ascent.
If a scuba diver ascends too fast, they risk bubbles forming which can be dangers. This is what's referred to as The Bends or Decompression Sickness. The deeper the dive, the quicker nitrogen gets dissolved into our body tissues.
This means that either the dive time has to be cut short or the dive must include decompression stops. By including decompression stops into your dive profile, you increase the risk.
Deep diving is not for everyone, but it's great for what you get to see. If you don't include deep diving in your scuba diving experience, you may be excluding some exciting dives. However, you can enjoy some really excellent dives at shallower depths too. Some of my best dives have been in less than 15 metres (50 feet).
Can a person die from the bends?
The short answer to the question of whether a scuba diver can die from the bends is yes. Therefore, scuba divers should avoid the bends at all costs.
The best case scenario of decompression sickness is for a diver to get what's known as a skin bend. A skin bend is a rash on the surface of the skin caused by the nitrogen escaping.
The worst case scenario in extreme cases for decompression sickness is death. For example in May 2009 a National Geographic diver died from the bends (decompression sickness) whilst filming in Greece.
There are around 300 reported cases of decompression sickness in the UK every year. The symptoms of decompression sickness can occur quite rapidly or they can take hours or even days after a dive before the sufferer becomes aware of their decompression sickness.
Deep diving tips
1. Deep diving is about safety first
As with all diving, safety is the top priority. However, as the risks are higher on a deeper dive, you should be more careful and receive the extra training required for this specialised scuba diving.
2. Planning your deep dive
As with all dives, a deeper dive should be carefully planned. If the deep dive involves decompression stops, these need to be worked into the dive plan.
The amount air of needed for the bottom time, for the ascent time and the decompression stop(s) time all needs to be taken account of.
Decompression tables should be used for this dive planning. These tables will provide the bottom time for each depth and how long before reaching saturation point and the point at which a decompression stop is required on the ascent.
3. Consider the diving conditions
When you're planning your dive consider where you are diving. Diving in the blue waters of the Caribbean or the Red Sea is a totally different ball game to diving at depth in the cold murky waters of somewhere like the UK.
If you're diving in colder waters you'll have more insulation and will be more buoyant to start with. This will in itself require more air than a dive to the same depth in the warmer Caribbean seas.
In UK waters there are also currents and tides to consider and slack time. You don't want to be diving on any wreck when the tide is running, let alone one that's at 40 plus metres (130 plus feet).
The other consideration is the visibility of the water. this will have an impact on how the dive goes. It may also have an impact on stress levels. Divers that stress consume more air and thereby reduce dive time. This needs to be avoided on a deep dive, as air consumption is sped up in any event.
4. Consider diver support and additional safety as a part of your dive plan
Consider additional safety tips. For example the dive boat should always have a supply of oxygen on board. This is needed for administering to a scuba diver that's come up too quickly from a scuba dive.
Also, consider the distance from your nearest barometric chamber or decompression chamber. These are extra safety precautions to allow for that just in case things all go wrong.
5. Plan the deepest dive as your first or only dive of the day
The deepest dive of the day should always be the first one you do. However, if you are planning an extra deep dive, consider only do the one one dive.
6. Consider a decompression station or a hang bar
You may also consider the option of a hang bar which can make it easier for divers to decompress. A hang bar is a bar set at the required decompression stop depth and is hung from the boat. Divers return to this and hold on until the end of their decompression stop.
The other alternative is a diver station, which is also set at the decompression stop depth. But in this case with extra safety air. This option is probably only really required for much deeper diving of over 50 plus metres (164 plus feet).
7. Don't dive deeper than your qualification level
Never dive any deeper than you're trained and qualified to do. This is for your own safety.
Also travel insurance will only cover you to the depth of your qualification. If something were to happen on a dive and it turned out you were diving deeper than your qualification allows, you'd not be covered.
This could be disastrous, as not only could you have been involved in a diver incident, but then your expenses would not be covered under the terms of your insurance.
8. Check your travel insurance
In a similar vain to the above deep dive tip, most travel insurances limit scuba diving to a depth of 30 metres (100 feet).
Never dive beyond your insurance limit, because if you do and something goes wrong, you'd not be covered by insurance.
But if you want to dive deeper when you are away on holiday or vacation, then take out specialist scuba diving insurance.
9. Back up air supply
When you dive deeper, its good safe diving practice to carry a spare air supply or 'Pony Cylinder.'
This pony cylinder is only to be used in an emergency, and not for a planned ascent and decompression stops.
10. Consider a technical diver course
Consider additional scuba diver education to learn how to dive with mixed gasses. These extend your range and will allow you to dive even deeper and explore those wrecks at deeper depths.
Very deep diving and extending your dive time at depth is only for those experienced scuba divers who have the necessary training.
11. Consider a rebreather
A good option for deep diving is a rebreather.
These require additional training, but are a good option for extending your dive time. However, you'll still need to carryout decompression stops on longer deep dives.
12. Use a delayed surface marker buoy
Many wreck dives will either have a fixed line to descend and ascend with or the dive boat will send down a line or their anchor.
But if this isn't the case (for example, you're diving from a rib), then always take a delayed surface marker buoy (Surface Sausage), to ascend with at the end of the dive.
This makes your ascent safer and easier and helps with decompression stops.
13. Prepare to send your delayed surface marker buoy early
Begin preparing your delayed surface marker buoy (Delayed SMB) early, as this can take a few moments to fill and send to the surface. In the time you are filling the balloon (sausage) with air and the time it takes to reach the surface you are racking up more bottom time.
If instead you start the process of deploying your delayed SMB at the point your bottom time has run out, you will add time to your ascent and decompression stop times. This will impact on your air consumption too.
14. Take two Delayed SMB's
Make sure as a dive buddy pair that you both have a delayed SMB. This is so that you each have your own line to ascend with. But of course ascend together and stop together for the same amount of time.
15. Delayed SMB maintenance
Make sure you maintain your Delayed SMB reel. Over time the sea water will encrust the mechanism and can cause it to jam. Make sure the real is in good working order, before you dive. This avoids it jamming at the wrong time.
You will not normally have time to spend sorting this out on the bottom, as your air will begin to run down. The longer you're on the bottom the faster your air will run out, plus you'll be racking up more decompression time.
16. Monitor your air very carefully
At depth your air consumption increases. Be careful to monitor your air consumption very carefully, as no stop decompression time runs out rapidly.
Also, once you enter decompression stop time, the amount of decompression time needed on your ascent racks up very quickly. So monitor this very closely along with your air consumption. You must make sure you have enough air to get you safely back to the surface with all the necessary decompression stops.
17. Take things very slowly
The deeper you descend on a scuba dive the quicker you'll consume your air. This is where conserving your air as a scuba dive comes into play and becomes extremely important.
You want your air to last as long as you can to extend the time you have at the bottom to explore what you've gone down to see, be it a wreck or the sea life down at that depth.
This is similar to monitoring your air consumption. At depth your 'no decompression stop time,' or the time you must stop for decompression on a decompression-stop-dive creeps up and speeds up very quickly once you move into this zone.
Never exceed your planned bottom time.
19. Dive with better insulation
The deeper you go the more likely you are of getting cold. This is especially true when diving with a wetsuit. The neoprene of a wetsuit gets crushed at depth and loses its insulating properties. If you are diving in colder water always dive in a dry suit at depth. You will be warmer.
More Reading: What is the difference between a wetsuit and a dry suit?
20. Build up to deep dives
Your body needs to adapt to deeper dives. Never dive straight to depths deeper than 20 metres (66 feet) without first doing a few dives at this depth.
Increase your depth gradually, after you've done a few 20 metres (66 feet) dives. Start at say 30 metres and do one or two dives at this depth. Then gradually get deeper.
If you are regularly diving in any case, you will be okay. But some think it's okay to go on holiday or vacation and do their first dive to 40+ metres (130+ feet) without any preparation. This is asking for trouble.
21. Know your equipment
In this article on scuba diving equipment, I discuss the benefits of owning your own equipment. This is important for safety, as you need to be familiar in an emergency.
This is even more important at depth, as things happen very fast when you go deep. The slightest mistake or going over your planned dive time can have serious ramifications. If you know your scuba gear, you are better equipped to deal with any situation. You'll be familiar with where everything is and do things without having to think to much or take extra time to do it.
22. Only dive in matched buddy pairs
Unless you are taking someone on their first deeper scuba dive and you are adequately trained and certified to do so, you should only dive to the depth you are both certified to dive to.
Never push the depth boundaries for any person. If your buddy can only dive to say 30 metres (100 feet), then limit the dive to this depth, even if your certification allows you to dive deeper.
This deep dive tip is for the safety of the both of you.
23. Are you going deep for the right reason
As I've already talked about, deeper is not always better. Diving deep is not always necessary and should not be a macho competition thing.
For example, I now pretty much limit my scuba dives to no more than 30 metres (100 feet). In fact, I can't remember the last time that I went over about 25-26 metres (80-85 feet).
So only dive deeper if you have a good reason to. For example, somewhere I've not yet been and would love to go is to Truk Lagoon. Whilst some of the wrecks are less than 30 metres (100 feet), many of the really good wrecks are below this and some are at 50-60 metres (164-200 feet).
If you are preparing yourself for a fantastic opportunity like this or the deep dive you are planning is something really exciting for you, then go ahead. But don't do a deep dive for the sake of it.
24. Be aware of nitrogen narcosis
Nitrogen narcosis is an alteration of consciousness at depth and is caused by the anesthetic affects of nitrogen.
Nitrogen narcosis can take on various symptoms, which can range from euphoria to depression or paranoia. Some people have been known to take their regulators from their mouths under its influence, not realising what they are doing.
Be aware of the symptoms for yourself and for your dive buddy and watch out for them.
If you feel them coming on, which can even happen as you descend. Stop your descent and ascend slightly before continuing your descent. This can sometimes clear the symptoms. The symptoms of Nitrogen narcosis clear very quickly normally, but they can cause problems if it's not spotted.
Preparing for a deep dive the night before will help. Get a good night sleep to help alleviate the onset of this phenomenon.
25. Make sure you're fully hydrated
Decompression sickness can be affected by dehydration. Leading up to your dive, make sure you drink plenty of water and stay hydrated to help prevent decompression sickness or the bends.
26. Get the right equipment for deeper diving
In order to dive deeper you'll need different equipment. You consume more air at depth, so you'll need to take more air down with you or use a rebreather. The minimum would be to use a twin set of 12 litre (80 Cubic Foot) dive tanks.
For this you will need two separate regulators, unless you have the dive tanks manifolded together.
27. Different dive computers
If you are diving with different dive computers, always go with the more conservative computer. So if your buddy's dive computer requires a longer decompression stop, both stop to decompress for the same time.
It's also prudent, as with all dives, to carry out an extra safety stop at 5-6 metres (16-20 feet) for 3-5 minutes too.
What type of scuba divers go on deep dives?
Deep dives are for the more qualified and experienced diver. You are limited to 40 metres with PADI and SSI for recreational diving, whereas you can dive to 50 metres as a Dive Leader with BSAC. However as a BSAC Advanced Diver you can go beyond 50 metres (164 feet) as a technical diver after following the appropriate training.
PADI also has a technical diving course where you can dive to 50 plus metres and even up to 100 metres (328 feet) taking their Tec 100 CCR course. SSI have a similar course to also extend the range of your diving and become a technical scuba diver too.
How deep can you dive without decompression?
All dives require decompression, as all dives are decompression dives. If divers do not follow correct decompression tables, they may end up with decompression sickness.
Why do you need to decompress when diving?
At depth the nitrogen in the air scuba divers breath is absorbed into the body's tissue. The reason this happens is from the increased pressure at depth. For example, at a depth of 10 metres (33 feet) the water pressure is twice the pressure at the surface.
On the ascent from any dive, a scuba diver has to ascent at a slow rate. An accepted ascent rate is between 9-10 metres (29-32 feet) per minute. Ascent rates are best monitored using a dive computer.
Any ascent that is faster than this could cause bubbles to form in the tissues of the body. This phenomenon is referred to as the bends or decompression sickness.
What is the no decompression limit?
Most of the dive centres refer to the 'no decompression limit' as what should actually be called the 'no decompression stop limit,' or what is also referred to as 'no stop time.'
The no decompression stop limit is the amount of time a scuba diver can stay down at depth without the need for a decompression stop.
Where a decompression stop is stop at certain depths to aid decompression. On certain dive depths and depending on the length of time the scuba diver spends at those depths, they may need to carry out decompression stops.
This could be to stop at say 9 metres (30 feet) for a set amount of time. These stops help to slow down the rate of nitrogen release from the body's tissues.
Decompression stop diving should only be carried out by trained scuba divers who have the correct level of certification. Decompression stop diving requires specialised training, as it comes with increased risks.
The training is required to minimise the risk associated with this type of specialised scuba diving.
To dive and not have to worry about a no decompression stop limit, you'd have to be diving at under 10 metres (33 feet). Although even at 10 metres you are unlikely to go into stop time before your air supply runs out.
How long is a decompression stop?
The length of each decompression stop depends on these factors:
- The depth of the dive.
- The length of bottom time on the dive.
- How many and to what depth the scuba diver has dived before the current dive, where they may still have nitrogen in their body tissues.
- Whether the dive is at altitude or not.
What is the deepest scuba dive?
The deepest scuba dive is a world record. This world record was set by an Egyptian diver who dived to about 1,090 feet in the Red Sea. This is the deepest dive ever by a scuba diver!
The funny fact about this extreme scuba dive was that it took Gabr just 12 minutes to reach the 1,090 depth, but then the rest of the day (14 hours) to ascent back to the surface again, to avoid any decompression problems.
Can you get decompression sickness in a pool?
Just in case you had this question as person looking to begin scuba diver training. No you can't get decompression sickness in a swimming pool.
I hope you enjoyed this article about what is deep diving…
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Have fun and be safe!