Dive gear for archaeologists part 5: Lights

The first question you may ask is why underwater archaeologists need a dive light to begin with? There are several good reasons why you should always carry one (or two) with you. First, we often work in places where visibility is severely limited, such as harbors or rivers. Sometimes we even work in overhead environments in complete darkness, such as shipwrecks and caves. Having a powerful light can help you find your way under water, and allows you to signal your buddy in case you lose each other. A light is a very useful tool in photography and videography as well, lighting archaeological artifacts and features to get better shots. Moreover, it is an important safety tool during bad visibility or stormy conditions on the surface, as it allows you to signal to other divers or boat traffic.

One key consideration we have as underwater archaeologists is that our gear should not be in the way. We are often dealing with many different pieces of equipment, which frequently need to be operated with two hands. A dive light is yet another piece of equipment, and it would be nice if that’s not in the way. Luckily, that is easily accomplished. Some lights come with a strap that allows you to carry the light on top of your hand, without needing to hold it. You could carry a dive light on each hand, and still have both hands completely free. This feature is indispensable for underwater scientists who need to have both hands available.

The next thing you need to decide when buying a dive light is whether you want an integrated battery or one that is replaceable. The big advantage of an integrated battery is that it’s convenient: you don’t have to mess around with opening and closing the light, and you don’t have to clean and grease o-rings. A replaceable battery, on the other hand, requires more work and has a risk of flooding, but the battery can be quickly switched out for a newly-charged one, allowing for back-to-back dives with the same light. What style you use ultimately comes down to your diving needs and personal preference. We are big fans of integrated batteries. As an archaeologist you need to be able to rely on your tools, and a light with an integrated battery never floods. This is especially important when working in remote places where a replacement light is not easily found. Moreover, there are so many factors to consider in underwater archaeology, so the easier the preparation and operation of a tool, the better it is.

Without going into too much detail, there are two things you should know about the beam coming out of your dive light. First, the output of a light is measured in lumens. Second, the beam has a certain width, which is called the beam angle. The amount of lumens is spread out over the beam angle, meaning that a 1,000 lumen light with a 10 degree beam angle produces a more concentrated beam than a 1,000 lumen light with a 20 degree beam angle – those lumens are spread out over a wider beam. Dive lights range from a few hundred lumens to several thousand lumens output. Beam angles range from about 8 to over 60 degrees. Of course, the more powerful beam a light has, the better. However, a more powerful beam usually comes at the expense of price, size, and weight. It is therefore important to weight these factors in your decision.

One other key consideration about a dive light is flexibility between beam angles. Some lights only produce a narrow ‘spot’ beam, while others allow you to switch between a spot and wider ‘flood’ beam. This function can be particularly useful if you want to illuminate a dark room in a wreck or cave, and when you want to use the light for photography or videography, when ‘flooding’ the scene with light gives you more flexibility in setting up a shot. Related to this is different intensity settings. Most lights have different settings for how much light they emit, which is a very useful feature. The higher the light intensity, the faster the battery will drain. You may want to use a low setting for most of the dive in order to preserve battery, and use a high setting for when you really need it.

Taking all of this into consideration, we have a few clear winners when it comes to dive lights for underwater archaeologists. While every light will be useful to some degree, not all are created equal. We are a big fan of Light & Motion, who produce a variety of lights. They even make dedicated videography lights, which have allowed us to capture some amazing footage over the years. All of their lights feature an integrated battery, can be mounted on a strap for hands-free operation, have multiple intensity settings, feature intuitive controls, and are very reliable. This is why we use Light & Motion lights exclusively, and have recently even become an ambassador for their brand. In our opinion, their lights represent the best value for money and offer all the features that underwater archaeologists need in a dive light. Our recommendation is a Sola Dive 2500 paired with a GoBe 800. The Sola is a powerful main light that can be used in spot and flood mode, while the GoBe is a perfect small backup light that can even be powered by USB. The GoBe can also be used out of the water, so it has become our go to flash light after a night dive or in any other dark setting. Together, these two lights got you covered for any project you do.