Turbid water can be a challenging environment for underwater photographers, particularly when shooting wide angle. Turbid water may not appear brown or green from the surface — in many cases the water looks entirely different once we drop in and begin the dive. All water is turbid to some degree. Understanding what causes turbidity and knowing how to work around it can make a world of difference when shooting in those conditions. One of the best skills a photographer can develop, particularly for shooting wide angle, is learning how to read water quality.
Thunder Bay National Marine Sanctuary in Lake Huron off the northeastern coast of Michigan has nearly 100 known shipwrecks, and others are still being discovered. The oldest shipwreck there sank in 1849, but many wrecks are from the mid- and late 1800s to the early 1900s. The location, history and variety of ships — from wooden schooners to freighters — make Thunder Bay special. The wrecks are at various depths, ranging from the snorkel zone to recreational and technical diving levels.
Sometimes life gets in the way — family obligations, unforeseen injuries, work responsibilities, social events — or perhaps the world as we know it shuts down for a while. When these things overwhelm us, many people tend to sacrifice exercise first. You may miss a few workouts, and then your exercise routine slowly slips from regular to nonexistent. It happens to most people — even fitness experts and professional athletes — at some time. Although it may feel challenging, it is possible to restart your exercise routine.
The first step in ensuring the safety of staff, divers and the public is to develop a detailed awareness of the real risks present in all operations performed by dive businesses and professionals. DAN® has produced a brief guide for anyone responsible for safety. The guide offers an introduction to identifying and understanding 17 of the most common areas of concern. These potential incident sources highlight the kinds of considerations that need attention and help operators to better understand how they might apply this knowledge to their businesses.
Interactions between different species, whether above or below water, typically revolve around confrontations between predators and prey. At the opposite and more harmonious end of the spectrum, a scattering of unrelated species coevolved to form lifelong alliances for their mutual security. These relatively rare go-along-to-get-along partnerships provide a net benefit for both parties, improving each species’ reproductive success. The close living arrangement between weak-eyed alpheid snapping shrimp and sharp-eyed partner gobies is a classic example of symbiosis in the sea.
Reduced exercise tolerance is common for those with chronic obstructive pulmonary disease and poses risks for diving. There can be strenuous activity involved with managing currents, swimming on the surface in choppy seas or pulling yourself and your heavy gear up a ladder and onto an unsteady boat. With COPD, shortness of breath during exertion doesn’t mean you are out of shape; it means you cannot rid your body of carbon dioxide and replace it with the oxygen needed to meet the demand of your exertion.
Gloves are one of the most overlooked and individualized pieces of dive equipment. When choosing gloves, consider the kind of diving you plan to do and what you expect from your hand protection. When selecting gloves, consider the following factors: thermal protection, fit, dexterity, hazard protection, impact resistance and materials.
Nitrogen narcosis can lead to deadly consequences. Understanding the risk factors and ensuring that you and your dive buddies have discussed how to mitigate risk can potentially save lives. If you are stung by a jellyfish, watch for symptoms associated with Irukandji syndrome. If symptoms develop, know that it is a potentially deadly condition that doctors can help treat. Pay attention to local marine life bulletins and announcements. The best ways to mitigate jellyfish envenomation risk are to wear full exposure suits and avoid jellyfish when they are prevalent in the water.
As you drop into water as black as night, thousands of pulsating squid in search of mates suddenly surround you. Mating activity is everywhere as multiple males attack single females. The excited squids’ chromatophores (pigment cells) flash colors reminiscent of a Las Vegas neon sign and put you in the middle of a living, moving light show. The action is so frenetic that animals are in your gear and bounce off every inch of your body.
During medical school Peter Lindholm joined a laboratory researching aviation, space and underwater physiology, where he developed a passion for breath-hold dive physiology, about which he wrote his doctoral thesis. As one of the physicians for the Swedish Sports Diving Federation (SSDF), he was involved in developing breath-hold dive protocols and training the first instructors of competitive breath-hold diving. After clinical training as a radiologist, Lindholm moved to San Diego, California, where he leads a research group focused on dive physiology and dive medicine.