Buying guide for best underwater lights
![Michael]()
Written by
Michael
Updated April 2022
Human beings rely on eyesight as our primary means of gathering information about the world around us. We can hear, but not like bats or whales that use sonar to navigate. Touch, smell, and taste are all short-range or useless for directing us from one place to another. So, imagine how critical it is to be able to see when you’re diving. If you’re exploring an underwater cave or reef, you’re going to need a waterproof underwater light.
“Swim on and don’t trust,” is an old French saying. It’s a typically Gallic expression of suspicion. When you’re swimming in the dark or wandering through the forest on a moonless night, you’re justified in being a little paranoid. It’s hard enough navigating your living room in the dark, let alone underwater. That’s where the right diving light comes in handy, and there are many to choose from.
It can be confusing to choose the right underwater light, even if you know what you’re looking for. We’ve compiled this buying guide to help you wade through your options.
Key considerations
If you’re cave diving or exploring reefs or sunken ships, you’ll need a flashlight no matter what time of day it is. Even examining the underside of coral outcroppings can require a flashlight. There are a few features to look for when shopping.
Size
The size of your flashlight isn’t usually an issue unless you’re carrying a lot of other gear, too. If you’re looking for buried treasure and taking a metal detector, or filming and carrying camera gear, then the size and weight of your flashlights will be an issue. Large flashlights weigh more than small ones. There comes a point when diving when you can be loaded down with so much weight that it starts to drag you down, and you’ll have trouble surfacing. If you’re going to be carrying a lot of other equipment, you should get the smallest flashlights possible.
Grip
Underwater lights usually have rubberized grips to prevent slipping. Some have pistol grips. Different people like different grips, so there’s no right answer on this one. It’s completely subjective, so get the one you’re most comfortable with.
Beam
The clarity of the water (or lack thereof) determines what sort of beam your flashlight should have.
Murky water: In murky or cloudy water, a narrow beam of light can carve through the gloom better than a wide beam, enabling you to see better.
Clear water: When you’re diving in clear water, a wide beam illuminates a larger area for greater visibility.
Depth
The ocean is roughly divided into three parts, or zones, based on depth and the amount of sunlight that penetrates to that depth.
Photic (or euphotic) zone: This is the uppermost layer of the ocean where there is enough sunlight to enable photosynthesis to take place. It reaches from sea level to a depth of about 200 meters (656 feet). The upper quarter of this zone is where most recreational divers should stay.
Disphotic zone: This is sometimes called the “twilight zone,” and it is an area of low illumination where there isn’t enough sunlight to enable photosynthesis. It stretches from a depth of 200 meters to about 1,000 meters (3,280 feet). None of the flashlights surveyed here will operate in this zone or deeper.
Aphotic zone: This refers to the deepest part of the ocean, below 1,000 meters, where the sun’s rays can’t reach at all.
Expert Tip
If you go deeper than the depth rating on your light, you run the risk of the light leaking, breaking, and malfunctioning.
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Features
Batteries
Flashlights always require batteries. There are three main types available for underwater lights.
Alkaline batteries: These are the regular batteries you see on the shelf in any grocery or hardware store. They don’t last as long as the other two types of battery and should never be used in your primary flashlight where battery life is critical. We recommend using these only in a backup or secondary flashlight.
Lithium-ion (Li-ion) batteries: These are good, middle-of-the-road batteries that have a decent battery life and a short recharge time.
Lithium-ion manganese oxide (LiMn) batteries: These batteries are the cat’s meow for discharge characteristics and battery life. They have the same recharge properties as Li-ion batteries, so they’re the preferred battery for your primary and therefore most critical flashlight.
Bulb
LED: These well-known semiconductors — light-emitting diodes — emit the brightest light of the three types of bulbs. They also use the least amount of electricity, so your batteries last longer. Except in special cases, the brighter your light the better. The cost savings from LED bulbs, along with their brightness, makes them the bulb of choice when you need to light up the ocean.
Xenon: These bulbs aren’t commonly used anymore. They’re not as bright as LEDs or HID bulbs, and they drain batteries faster than either sort. However, photographers like them because they have a warmer light for videos and still pictures. They’re not easy to find, but if you’re taking a lot of pictures, you can put these bulbs in your backup light and use it just for taking pictures.
HID: High-intensity discharge bulbs are relatively unknown these days. They use a gas between two electrodes that light up when a spark jumps from oneelectrode to another. It takes the bulb 15 to 20 seconds to build up to full intensity.
Beam angle
You need an underwater light that has both a wide and narrow beam. Look closely at the description and make sure the beam angle is adjustable. Most of them are, but it never hurts to check just in case.
Wide: When you’re descending or ascending, a wide beam angle provides the best illumination without giving you a “tunnel vision” effect. At night, you need the widest beam angle you can get.
Narrow: Once you reach your underwater destination, you need a narrow beam when going through caves or wrecks because it lets you see as far ahead as possible. That helps you chart your course through the passageway.
Expert Tip
Your backup light should be smaller and less expensive than your primary light.
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Accessories
Gear retractor: Hammerhead Industries Gear Keeper
Secure your flashlight, yet have it readily available when you need it. This retractable tether has a quick disconnect and a 32-inch line.
Flashlight holder: ORCATORCH Diving Flashlight Holder
Wear it like a glove and this flashlight holder can keep your flashlight securely attached to the back of your hand. It holds flashlights from 0.94 inch to 1.10 inches in diameter.
Underwater light prices
Inexpensive: The low price range for underwater lights is $10 to $50. Several of our choices are in this range, and any one is sufficient for beginning divers or as a backup light.
Mid-range: The medium price range is $50 to $150. Any flashlight in this range is suitable for just about any diver.
Expensive: Above $150 is where you find professional-grade underwater lights that will last for years.
Expert Tip
If you don’t have a lanyard on your light, you’re begging to lose it to Davy Jones’ Locker.
STAFF
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Tips
- Keep a lanyard tucked away when diving. If you’re using a lanyard so you don’t lose the light, don’t let it dangle and bump into things while you’re diving.
- Use an adjustable light. A low-power beam won’t scare animals and fish as much as a bright, powerful one. Get an adjustable or low-power light if you’re looking for wildlife.
- Never shine your light in another person’s eyes. It will ruin their night vision for several minutes, which is very dangerous underwater.
Other products we considered
If you don’t see what you need in our matrix, we have a couple other products for you. We like the rechargeable VOLADOR Professional Diving Light. It is rated to a depth of 100 meters (328 feet) and has three LED bulbs. The brightness can be adjusted to high, medium, and low (3100, 1200, and 350 lumens), depending on the diving conditions. On the low setting, the batteries will last for 5.5 hours, which makes it a decent primary diving light.
We also like the Underwater Kinetics Dive Light with its pistol grip. It gives you the option of choosing between an alkaline battery model (C batteries) or one with a rechargeable battery pack. It is rated to a depth of 152 meters (500 feet), and on the low setting, the C batteries will last 20 hours. Even on the high setting, the LED bulbs will keep burning for nearly 6 hours.
FAQ
Q. How many underwater lights should I carry with me on a dive?
A. Two. One is your primary light and the other is the backup. The backup can be smaller than the primary, but never go diving with fewer than two lights, especially at night or when cave diving.
Q. How should I take care of my underwater light?
A. You need to check it before and after every dive. Disassemble it after each dive and clean it thoroughly. Recharge the batteries or put in fresh ones. When you reassemble it, ensure that the O-ring is completely clean and coated with silicone grease to prevent leaks.
Q. Do I need an underwater light in warm, clear waters like the Mediterranean or Caribbean?
A. Probably not if you’re diving during the day. But if you find a cave you want to explore, you’ll need a light, so you should always take one with you just in case.
