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Thermal Night Vision Technology

Of all the systems labeled "night vision," long wave thermal is the most valuable, sometimes even during the day.
Boating Safety

In fact, there's a lot of value to two or more cameras in the same case. Some manufacturers add full-color HD cams or the light-intensification technology that's more commonly seen in night-vision monoculars. In the case of the FLIR M-636L, the low-light cam sometimes served well as elaborate binoculars, even if it couldn't see beans in dark-as-apocket conditions. Meanwhile, the thermal cam showed daytime uses beyond seeing through "dry" fog, like when I was unhappily driving straight into a wide swath of sun glare until I realized that the FLIR microbolometer ignored that glare altogether, revealing pot buoys as well as it did at night.

Because that microbolometer can turn slight differences in radiated heat into monochrome video, things that are especially hot relative to a scene, like a human most anywhere, tend to stand out vividly. The default set the image to hot as white, but I found hot as black more "realistic" looking. Day or night, I could more quickly identify human activity around my harbor with the thermal camera than with any other form of vision aboard. This, and the fact that thermal cameras can also track hot objects like exhaust pipes well, is why they caught on first for security and military uses, and hence why the performance of the M-636L is slightly, if artificially, throttled.

Because of the FLIR microbolometer's relatively high resolution, the U.S. government insists that any system using it be limited to nine frames per second instead of the normal 30 frames, which their testing has deemed too powerful for civilian hands. Frankly, I found this slow refresh rate very hard to notice unless a boat passed close and quickly by, but it's the sort of thing you might want to know before making a large thermal investment. Casings and controls are definitely worth thinking about, and I suspect the FLIR MSeries is a good reference design.



For one thing, the M's bullet casing, only 11 inches tall and seven in diameter, lets the cameras freely rotate 360 degrees and tilt more than 90 degrees without bumping into anything. In other words, you can mount an M-636L under most open-array radars or alongside thin antennas if that's what it takes to get the best crow's nest view from your yacht. I also found the control unit's variable speed puck and the on-screen graphic references just about right for pointing the camera's 26-degree field of view where I wanted it. And using Ethernet to power and interconnect multiple controllers within a camera system makes for a tidy install and may pave the road for M-Series features not seen on the M-636L.

More features? While FLIR has redefined what's possible in this price range, higher-end night-vision systems offer valuable integration with radar and AIS-like automated pan/tilt to a selected target- and desirable options like gyro stabilization (peering around from the crow's nest while your stomach is in the pilothouse can be unsettling). One place to see what more money can buy is FLIR's own Voyager Series (, but you should also check out OceanView Technologies (, NVTi (, and Current Corporation ( While I suspect that we'll be seeing continually better and less expensive thermal vision products for years to come-with FLIR often leading the charge-Current is working on new night-vision technology that will purportedly use timed laser illumination to see right through even heavy fog and rain. That might change the game.

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The U.S. Coast Guard is asking all boat owners and operators to help reduce fatalities, injuries, property damage, and associated healthcare costs related to recreational boating accidents by taking personal responsibility for their own safety and the safety of their passengers. Essential steps include: wearing a life jacket at all times and requiring passengers to do the same; never boating under the influence (BUI); successfully completing a boating safety course; and getting a Vessel Safety Check (VSC) annually from local U.S. Coast Guard Auxiliary, United States Power Squadrons(r), or your state boating agency's Vessel Examiners. The U.S. Coast Guard reminds all boaters to "Boat Responsibly!" For more tips on boating safety, visit

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