Even on a sunny day, the sun’s rays can penetrate only so far into the water, making diving lights a vital part of your scuba gear. Night lights are essential safety equipment on a dive for a number of reasons:
1) They are important if you are in dark conditions. Night diving, low visibility environments, cloudy days, and shipwreck and cave diving are simply not possible in most cases without good diving lights.
2) They are important for sudden changes in visibility. The greater your depth on a dive, the more likely you are to need a light. The sun’s rays simply cannot make it through water that deep. Even if you stay in shallow waters, a sudden bloom of algae or a sudden change in lighting conditions can make it suddenly dark.
3) They are crucial for signaling. If you need to communicate with a diving buddy on a dive (or even on a boat before a dive in the dark) a flashlight or light can come in handy. In a pinch, diving lights can be your communication device, and can even be used to signal an emergency to a diving buddy.
4) They can help you look at your equipment underwater. If your air gauge or compass is not backlit, that diving light is crucial for your safety as it will allow you to take a closer look at your diving gear when you need to.
5) They can help you see the red end of the light spectrum. This part of the spectrum of light is not visible underwater, even in clean and shallow waters.
If you want a flashlight for your house, you probably don’t put much thought into it. You head out to the hardware store and pick up the first light that suits your style and budget. A diving light, because it is an important part of your safety equipment, requires a little more forethought. When choosing your diving light, look for:
1) Primary and back up lighting. You will want to have a larger primary light for lighting your way under water, but you will also want to look for a smaller light for emergencies and in case your primary light stops working. Diving lights are so important that you will want a back up lighting system. Smaller back up lights are also good for peering into crevices and exploring underwater.
2) Beams. Most diving lights offer either wide beams or narrow beams. Wide beams will shine a light over a larger area but will be a little larger. Wider beam lights are good as your primary lighting system as they will allow you to see what is in front of you more clearly. Narrow beams are smaller, usually brighter, and are good as a back-up lighting system. They can help light up tiny details – like a small crab by your feet – and in a pinch, they can help you see your gauges and compass.
3) Depth rating. Diving lights come with depth ratings, indicating the maximum dive depth safe for the light. You need to determine your maximum diving depth not only now but also in the foreseeable future, so that your light will be able to handle the depth you need. If you try to dive with a light not designed for your dive depth, your light will malfunction. It could even break or leak. It is best to buy a light for a slightly deeper dive than you intend rather than risk being without a light.
4) Steady or strobe lights. For most diving lights, you will want a steady light which lights up your way and lets you see under water. However, if you are diving with a buddy and want to be able to see each other at all times, it is useful to attach a smaller strobe light to each tank – that way, each of you will be able to see the other, thanks to the flashing strobe light.
5) Batteries. Diving lights use alkaline, NiCad, and other types of batteries – just like your average flashlight. You may want to consider the cost of battery replacement when purchasing your diving lights. You will also want to note the batteries of your diving lights so that you can have plenty of spare batteries on hand in your dive bag. If possible, choose your primary diving light and backup diving light so that they have the same type of battery. This way, you won’t have to carry two types of battery back-ups.