The infrared-assisted Cam100 ($700), and the many like it, are darn useful around a boat, but they can't hold a candle, so to speak, to infrared thermal cameras like the FLIR M-636L ($20,000) and its brethren. The longwave- thermal portion of the infrared-wave band is totally unrelated to visible light or the digital cameras that can see it. Thermal infrared is instead related to the internal molecular heat of an object and is emitted by everything, including icebergs. The sensor that can feel it, called the core, is a very exotic bit of tech, and thus somewhat crude even at this price. In fact, the M-636L's 640-by-480-pixel microbolometer core smashed a price barrier as other marine cameras in this range, and higher, had typically offered 320-by-240-pixel image resolution. Many of those competitor products have caught up now, often using a FLIR core. The quadruple resolution improvement is definitely noticeable, and increases the range at which a danger can be noticed and identified. But 640-by-480 is still low-res in modern video terms, and that's one reason that many marine night-vision systems like the M-636L pair a conventional low-light video camera with the thermal sensor.