Fact number one: Of the 5,191 boating accidents logged in 2007 by the U.S. Coast Guard, more than one in 10 happened after dark, even though the majority of boats are thought to be off the water by nightfall. Fact number two: If you plan on navigating after the sun sinks below the horizon, you need every advantage on your side – and night vision gear is a tremendous asset for boaters.
Luckily, we have GPS, color chartplotters, computer programs, and highly detailed cartography chips that make it relatively easy to figure out exactly where you are. Running aground or smacking into a jetty that you can't see by starlight isn't nearly as likely as it once was. But floating objects, improperly lit boats and uncharted obstructions are still major dangers to the night-time boater. There are also emergencies, such as a man-overboard situation, when being able to see through the darkness would be a huge advantage.
FLIRAt left, the view to the naked eye. At right, a thermal image of the same view. Which would you prefer?
Much like the evolution of the GPS, which was once bulky and expensive, modern advances have brought compact and affordable night vision to everyday mariners. Quality gear is not cheap, and there is some learning to do in order to select the proper equipment. But the advantage is that there have never been more options available to those who travel at night.
NV VERSUS IR
The term night vision is somewhat misleading. It's often applied to any type of gear you'd use to see in the darkness. In fact, what we call "night vision" can be one of two distinctly different technologies: devices that gather and intensify low-level ambient light that exists from the stars, moon, and reflections, or thermal-based devices, which convert a thermal image into a picture that's visible to the human eye.
BUSHNELL1 = Image intensifier screen. 2 = Phosphorous screen. 3 = Objective lens. 4 = Infrared illuminator.
Most common are the inexpensive night-vision scopes – monoculars and binoculars – which work using the light-gathering technologies. Binoculars tend to be more expensive, since they require two complete optical devices. They are notably more comfortable to use, however, as peeping through a single eyepiece does become tiring after a while. In either case, the unit has three main parts: an infrared illuminator, a phosphorus screen and an optical lens.
The infrared illuminator essentially provides a light source that works with and boosts ambient light, and improves the images of objects between 50 and 250 feet away. The phosphorus screen and optical lens are contained in the "image intensifier" (the barrel-shaped section of the unit), which gathers the light's photons and converts them into electrons. When these electrons are beamed against the phosphorus screen, they create those greenish images we've seen many times on TV, when video is filmed with night-vision gear. Peep through the scope of this type of night-vision gear, and that ghostly greenish image is what you'll see.
These basic night-vision units are called Gen I (for first-generation), and they can amplify ambient light several thousand times. Though their imagery is fairly sharp, many Gen I units appear fuzzy around the edges due to geometric distortion. Another flaw most exhibit is the presence of small black spots, which always appear in the scope. They aren't large enough to affect usability, but they are an annoyance.
ATNThe ATN 6015, a Gen II night scope.
Some common examples of Gen Is include the Bushnell Night Vision 2x24 Monocular (about $160, available at opticsplanet.com); the Newcon MB-3 Nightscope ($329, available at West Marine) and Night Owl Optics Explorer Marine ($250, available at Boater's World). Like most Gen I's, all of these units have fairly low magnification (2X for the Bushnell, 2.4X for the Newcon, and 3X for the night Owl) and wide fields of view. The Newcon and the Night Owl are also waterproof and will float, features that are quite important to boaters, especially those who may use these units in a small, open vessel.
All three of these units share one more important feature: They're relatively cheap. Ten years ago, it would have been impossible to acquire night-vision gear for a few hundred dollars. In fact, you would have had to spend a few thousand. If your budget allows, however, more modern Gen II, Gen III and Gen IV gear is now on the market. Naturally, the more advanced, the more expensive it is.
GEN II, III AND IV
Gen II units work on the same basic principals as Gen I, but add a micro-channel plate (MCP) to the image intensifier. The MCP consists of fiber-optic tubes – millions of them – which boost the available light significantly, creating an image that is brighter. Sharpness of the imagery is also improved, especially around the edges, where blurring is an issue on Gen I units. Fujinon's Gen II PS910 Starscope (between $1,500 and $2,000, available at both West Marine and Boater's World) is one example of this type of unit. It is waterproof, corrosion-resistant, and lightweight, and it offers both 1X and 3X magnification. If you're willing to up the ante by another thousand dollars or so, you can get a Gen II unit like the ATN 6015-CGT, which can be handheld, head-mounted, or adapted to cameras and camcorders.
