+ How does AirBuddy work?

Simply put, AirBuddy is a battery powered dive compressor. The rechargeable 12V battery stores energy. This energy then powers the air compressor to pressurise the surface air. This pressurised air is then delivered to the diver through a supply hose with a regulator (mouthpiece). It's a simple concept, really. However, to make AirBuddy small, light-weight, powerful and durable, we had to go to great lengths to find the right components, materials and manufacturing processes. If these were nowhere to be found, we invented them.

+ Why do I need to breathe pressurised air when diving?

As humans, we have evolved to live above the surface. The atmospheric pressure on the surface is about 0.5 - 1 bar (depending upon altitude). However, the pressure underwater is higher. The weight of water adds 1 bar of pressure for every 10m of depth. This pressure is pushing against our body. It doesn't affect our body parts that are solid or liquid, because they are, by law of physics, incompressible. It does however affect the air spaces in our body, and therefore our lungs, because air, as any other gas, is compressible. So we need to breathe air at the same pressure as the surrounding water; enabling our lungs to work properly. In other words, we can't breathe air at a lower pressure than our surroundings, simply because our muscles are not strong enough to force our lungs open, pushing against the water pressure.

+ Is diving with AirBuddy different from FreeDiving?

It is fundamentally different from freediving (breath-hold diving), and we would like you to understand the difference as it is important for your comfort and safety. With freediving, you inhale surface air at normal atmospheric pressure, then hold your breath and as you descend, the water pressure shrinks your lungs. As you ascend, your lungs expand back to their initial size. In contrary, and similar to SCUBA, when diving with AirBuddy, you breathe in compressed air so that your lungs can operate at their normal capacity, even though at depth. Therefore, you must NEVER hold your breath on ascent! You have to continuously breathe in and out to allow the air pressure in your lungs to adjust to the surrounding pressure. If you were to hold your breath and ascend, the air in your lungs could expand to a volume larger than the capacity of your lungs and you risk lung over-expansion. If continuous breathing is not possible, e.g. due to an emergency, slowly exhale (making an aaaaaaaah sound) on ascent. This is the most important rule of diving and you need to remember this.

+ Is diving with AirBuddy different from SCUBA?

The similarity with SCUBA is that you breathe compressed air. Other than that, it's quite different. With SCUBA (self-contained underwater breathing apparatus), you take all the air you'll need during your dive with you, in a steel or aluminium tank. A standard Al-80 tank with 11 litre internal capacity can store about 2300 litres of atmospheric air, when pressurised to 210 bar. This extremely compressed air is then slowly released through a 2-stage regulator for breathing at the required pressure. With SSBA (surface-supplied breathing apparatus), you only compress the air to the pressure that is required for diving itself, not storing of the air. The pressure in the system is therefore much lower. AirBuddy is set to provide air at about 2.6 bar to allow you to dive up to the depth of 12m for about 55 minutes. In fact, the SSBA has been around for longer than SCUBA. What makes it really interesting now is that in combination with the latest technologies and advanced materials, it is possible to manufacture a compact diving device - AirBuddy.

+ Why can't we just make light-weight SCUBA tanks?

You need a lot of pressure to pack a large volume of air into a relatively small space ("tank" or "cylinder"). The SCUBA tanks are typically filled to about 210 bar pressure (some tanks even higher). To withstand this extreme pressure, the tank has to be made of a very strong material. SCUBA tanks are typically made out of aluminium or steel with thick walls that make it heavy. A standard Al-80 SCUBA tank weighs about 17.5kg, a steel tank of the same size about 20kg (when full). Some could argue that there are also lighter tanks, such as the composite tanks used by fire-fighters. However, these are not suitable for diving because of their buoyancy. Let’s use an example using the Archimede’s Principle - a tank with external volume of 15L displaces 15L of water when submerged. 15L of sea water weights approximately 15kg. Therefore, this is exactly how much your tank needs to weigh to be neutrally buoyant (neither float, nor sink). So having a lighter tank wouldn't do the trick. You would need to take extra weights with you equal to what you have just saved on the tank.

+ How is it possible that I don't need BCD for AirBuddy?

When you dive with compressed air, your lungs operate at their normal capacity, i.e. they don't get squeezed like they do with freediving. The composition of your body (the proportion of solids, liquids and gases) is practically constant, hence your total body volume and buoyancy (the ability to float) is constant as well. What's changing buoyancy is your SCUBA tank. The tank is filled with a large volume of air. A standard Al-80 tank contains about 2300 litres of atmospheric air, when pressurised to 210 bar. 1 litre of atmospheric air weighs about 1.286g, so the 2300 litres of air inside your tank weighs about 2.9kg. As you consume this air, your tank becomes lighter, thus more buoyant. Since you don't use a tank when diving with AirBuddy, you only need to adjust your buoyancy once, at the beginning of your dive with the right amount of weights.

+ Does my bottom time depend on my air consumption?

No. This is different from SCUBA where your amount of air is limited to what is inside your tank. With SCUBA, the more you breathe and the deeper you go, the shorter your diving time. AirBuddy's compressor continuously provides more air into the system, hence your diving time is dependent on the AirBuddy battery capacity rather than your breathing or the depth of your dive. The maximum dive time with a fully charged battery is about 55 min (plus reserve). However, your maximum depth does depend on your individual air consumption. Various factors contribute the your air consumption, such as experience, activity level, body build, water temperature, etc. Our depth rating is based on 24lpm SAC.

+ How long does the battery last for?

According to our testing, we've recorded about 65 min; this is from a fully charged battery to a level when AirBuddy stops. However, you should not be diving until the device stops. Therefore, we've built in a battery level monitor that starts sending audible signals when the battery voltage drops below certain threshold, which is after about 55 min of operation. This is the signal for you to ascend.

+ How do I recharge the battery?

Simply plug the charger into a wall socket and connect to the battery. You can recharge it at home or even when travelling in a campervan or on a boat, either with AC mains outlet or using the optional 12VDC charger. The full battery recharge takes approximately 5 hours.

+ Can I replace the battery and go for a second dive?

Yes, absolutely. This is the best thing about AirBuddy. Additional dives with SCUBA require additional tanks, hence some 18kg extra weight for each tank to carry. For an additional dive with AirBuddy, you only need an additional battery that weighs approximately 2.9kg. AirBuddy comes with one battery included; though you'll be able to order additional batteries should you wish to do so. To change the battery - open the lid, disconnect the cable terminals, replace the battery, reconnect the cable terminals and close the lid again.

+ Can I take AirBuddy with me on a plane?

Please note that the transportation of lithium batteries is subject to dangerous goods regulations. You should always check the instructions in the Dangerous Goods brochure of your airline and present the battery at the check-in. Most likely, you will be required to transport the battery in your cabin bag and asked to prevent short circuit by taping over the exposed battery terminals or placing the battery in a plastic bag. We designed the battery to comply with the 56th edition of Dangerous Goods Regulation published by IATA. Some airlines may however decide to apply additional rules, so please always check with your airline.

+ What does AirBuddy sound like?

You will hear 3 different sounds when diving with AirBuddy. Firstly, AirBuddy makes a gentle buzzing sound when the air compressor operates. It is similar to the sound of a small boat when passing by in the distance. It is good sign when you hear this sound because it means that the device is working. The second sound, which is louder than the first one, is the sound of your own breathing – a sipping sound of the regulator when you breathe in and a cracking sound of the bubbles when you breathe out. The third sound will not be present most of the time. It's the sound of AirBuddy’s low battery alarm that is triggered when the battery goes below certain threshold, after about 55 min of diving. It is the signal for you to ascend. None of these sounds appear to disturb underwater wildlife, so don't worry - you'll have an amazing dive!

+ How strong is the hose? Can it get tangled?

The hose is made from strong polyurethane. It's abrasion and kink resistant. It's operated at a lower pressure than 1/4 of it's rated working pressure and at a fraction of it's burst pressure. A recoil (spiral) hose has the advantage over a straight hose that it tends to stay organised, keeps AirBuddy at a closer perimeter from you and acts like a suspension to smoothen out any potential tugging caused by swell or your swimming. It's positively buoyant, so it points upward from the diver's back. When diving together with your buddy, you can link 2 AirBuddies together. They will float in a formation to lower the risk of entanglement of the hoses. Even if the two hoses crossed, it shouldn't stop the air flow as you need substantial force to kink the hose. Since you are tethered to the surface, we do not recommend diving with AirBuddy in obstructed environments such as caves, wrecks or kelp forests.

+ How do I maintain AirBuddy?

AirBuddy has a simple, but robust design. It will last for a long time if you look after it properly - rinse in fresh water, store in a dry place without direct sunlight, keep the battery recharged, etc. But one day, some parts may get damaged, lost or worn out, so we will provide the option to order spare parts. Many of the parts can be easily replaced by the user without any tools; although, some will require a little knowledge and the use of a few standard tools. All in all, we believe repairing AirBuddy is easier than repairing a bicycle. Unfortunately, we are not in a position at the moment to establish our own network of service centres, but are more than happy to provide instructions, training and parts to any existing service centres, dive shops and alike if they wish to service AirBuddy. Of course, there is always the option to send your AirBuddy to us and we will repair it for you.

+ Do I need a dive training?

Absolutely yes! But "having the plastic card" is no guarantee for your comfort or safety. You really need to understand it. Use all the means available to you, including a training course, a book, an experienced friend and online resources to learn and understand the diving theory and develop and frequently refresh the required diving skills. Please remember, there is no harm in practicing your first few dives with AirBuddy in waist level water. Why not start in 1m depth and then go to 2m, 3m, ...5m, ...10m or even deeper as you gain more confidence? It's about you and your safety! Please dive responsibly.

+ Is diving with AirBuddy safe?

No matter what sport you do, whether you play soccer, ride a bicycle, swim or ski, there are always some risks involved. The most important thing for your safety is that you always understand the theory and obey the safety rules. Diving is no different. Please use all means to learn, practice and acquire the required skills. Dive responsibly, know your limits and never go to a depth you don't feel comfortable to ascend from without any air supply. Wear a small redundant system, such as the Spare-Air. Some of the active and passive safety features are:

• removable magnetic switch to ensure that only you (the diver) can switch AirBuddy off
• low battery alarm to inform you of depleting battery
• large 16L air reservoir to provide a few breaths in case of an emergency, enabling you to safely return back to the surface
• visible float and diving flag to mark your position to boats, fishermen, etc.
• limited depth by the length of the supply hose
• precise design and robust construction

+ Do I have to be careful about decompression sickness (bends)?

With AirBuddy, you dive deep enough to explore the beauty of marine life, but not deep enough to run a high risk of decompression sickness, also known as "bends". This is how it works: You breathe compressed air when diving. Breathing air that is "thicker" means that your body tissue absorbs more nitrogen compared to when you are on the surface. How fast and how much nitrogen your body absorbs depends upon the depth and dive time. The deeper and longer you stay, the higher the amount of nitrogen is accumulated in your body tissue. PADI recreational dive planner suggests that you can dive up to 2 times with AirBuddy (55min at 12m) and still be able to return directly to the surface without making any decompression stops. As a precaution, we recommend making a safety stop (3 min at 5m) at the end of every dive or plan your dive profile so that you finish diving in shallow water. You shall not exceed the maximum ascent rate of 18m/ 60ft per minute recommended by PADI (i.e. 10 sec from 3m depth, 20 sec from 6m depth, 30 sec from 9m depth, 40 sec from 12m depth).