General Info – Page 9 – Dive To Escape

A good dive computer can really add a lot of enjoyment and peace of mind to your diving. That’s why I want to give you an idea of what to look for in a dive computer. Whether you're diving less than 10 times a year and think you will only be diving on vacations or if you plan on being a regular cold-water diver, in both situations, there are affordable durable computers that will grow with you in your diving. Features your dive computer needs to have: -Bottom timer -Continual calculation of no-decompression limit -Surface interval timing -Nitrox -Electronic dive log Most training now makes a dive computer a necessary piece of equipment. PADI’s latest standards don’t even cover dive tables, making dive computers mandatory. Regardless of the requirement, one main reason for me personally to get a dive computer is efficiency. Dive computers normally calculate your NDL (Non-Decompression Limit) constantly so you are getting the most efficient use of your air relative to your NDL. This way if you're within recreational limits, you can dive as long as possible on the gas supply you have compared to dive planning with a dive table where you plan your dive as though you will just go down, touch bottom and come up. Doing a multi-level dive with the computer gives you a representation of your CO2 exposure so that doing multiple dives in a day is both easier to plan and safer because the dive computer will also keep track of your surface interval time. Dive computers are able to do this using different algorithms that simulate how the tissues in your body absorb CO2 and release it. Some of the algorithms are more conservative than others. For recreational diving, which algorithm your computer comes with may not interest you much, but if you go into technical diving, some divers like to have a computer with options on which algorithm to run for which dive. You can read more about the different types of algorithms if you follow the link, as it is more than the scope of this article can cover. https://dipndive.com/blogs/dive-gear/dive-computer-algorithms-for-dummies Bottom Timer All dive computers should have a simple bottom timer function, which is just the depth and time durations of the dive. These two pieces of information are very important. Even though your dive computer will continually calculate your NDL, before you start any dive you should plan your dive and give yourself an idea of how long you could stay at the max depth, just in case your computer has some failure you will at least know the max time at depth. Doing a dive plan before a dive creates an extra layer of safety through redundancy should any of your equipment fail. Surface interval, interval time on the surface between dives Having a dive computer that will start a clock as soon as you surface from a dive is a really helpful feature too. This is because, if you are doing multiple dives in the same day, knowing your actual surface interval is an important safety factor for your successive dives and having a computer that calculates that means it will automatically factor it into your NDL once you start your next dive. For someone who plans on travelling, this is a must-have feature as it will give you a good approximation as to when it will be safe to fly again. Some computers even have a fly clock, which is just a clock that counts down to when it would be safe for you to fly after a day or week of diving. Nitrox Whether you plan on just diving on warm vacations or you plan on being a recreational diver in cold water, always get a computer that is nitrox compatible to at least 40%. You will not regret it. This feature normally comes with the most basic of computers, but I would hate for you to miss out on a dive simply because you didn’t have a compatible computer. Nitrox makes diving safer in some senses and, if you plan on doing repetitive dives, may leave you less fatigued. So having a computer that has this feature is always helpful. Click here to read more about nitrox and why you should get certified. Digital dive log As I have said before it’s important to have a paper dive log to back up your digital dive log. However, having a dive computer that tracks everything for you and can just be downloaded to your computer or app is very practical. The log interfaces are normally user-friendly and have a neat graphical representation of the depth profile of your dives. They will also have other helpful information like surface temperature, water temperature, and sometimes a lot more depending on any extra features or accessories your dive computer may have. It is much easier than to transfer this information to your paper dive log. There are many factors that make a dive computer a must if you plan on diving semi-regularly. The above features are a basic list of must-have features if you plan on choosing your own so that you have a functional and enjoyable piece of dive equipment. The list of all the features that are available is huge and gets better and better every year. Here are just a few of the features available that, while not necessarily critical, are nice to have. Colour digital screen This is a nice feature as it’s just easier to look at a colour screen than the standard digital screen, but also the colour screens are often bigger. Additionally, if you're a cave or wreck diver, these colour screens are so bright they can serve as a tertiary backup light in the case of a catastrophic light failure event. Large buttons Large buttons along with easy-to-navigate menus can be a real benefit for a cold water diver. We often have thick gloves on making it hard to click through menus at depth. Integrated compass An integrated compass is definitely not a necessary feature as one should always have an analog compass on your console or better yet on your left hand. That being said, having a backup compass in your dive computer is a nice feature because it’s just that much more convenient and functional. Some computers with this feature allow you to set your heading which makes navigating even easier as all your dive information is on one screen. So while I wouldn’t say a compass is a deciding factor in choosing a dive computer, if it already comes with the computer you desire, I think you’ll enjoy the added benefit. Air integration and the ability to calculate SAE (surface air consumption) This is a feature that more and more computers are coming with. Air integration is normally an add-on, where you attach a sensor to your tanks and the dive computer will give you a live reading of the pressure left in your tanks. The computer will also usually give you a display of the duration of your dive remaining based on the air you have relative to your air consumption. Personally, I really like this feature simply because I like data and I like that it will calculate your SAC rate BUT I do not rely on the dive time remaining relative to my air remaining as this is just an approximation on the computer and I always dive in thirds because that is the safest procedure. Something to keep in mind is there are dive groups and dive associations that don’t support the idea of air integration as it is not 100% reliable. It can stop reading at times for a minute or two or, if you enter a wreck, some metals will affect the sensor, although normally not for long at all if it even happens. This is not an acceptable occurrence for those groups and agencies, as having something like that happen in a cave or deep in a wreck can just add a failure point or confusion point to the diver. Personally, I feel for recreational diving this is a great fun feature and one should be familiar with both its limitations and uses. Heads-up display: The heads-up display is a feature newly available for rebreather divers where the computer has a small screen with all the information you like attached to your breathing loop keeping it within the diver’s field of view so they aren't looking away like when looking at a wrist-mounted computer. Technical computers: Technical computers are dive computers that have algorithms that are able to calculate several breathing gasses at the same time and calculate decompression stops. These are powerful units, some are more complex than others but if you think you might grow into technical diving there is nothing wrong with buying a quality technical dive computer that you can grow with. A dive computer can be quite pricey and not all computers are the same, here is my list of recreational nitrox dive computers and recreational technical computers. Entry-level dive computers $0-350 https://www.amazon.ca/Suunto-Zoop-Wrist-Computer-Watch/dp/B019YLOZS8/ref=sr_1_3?ie=UTF8&qid=1548110363&sr=8-3&keywords=dive%2Bcomputer&th=1 https://www.amazon.ca/Cressi-KS770150-Leonardo-white-black/dp/B0065PPJ1E/ref=sr_1_2?ie=UTF8&qid=1548110363&sr=8-2&keywords=dive+computer https://www.amazon.ca/Mares-414135-Puck-Pro-Plus/dp/B01M06QP5M/ref=sr_1_4?ie=UTF8&qid=1548110363&sr=8-4&keywords=dive+computer https://www.shearwater.com/products/peregrine/ Technical/Recreational Computer https://www.shearwater.com/products/perdix-ai/ https://heinrichsweikamp.com/ostc4.html https://eshop.divesoft.com/ca/deco-computers/freedom-closed-circuit-without-cable/8272