The best technology choice for the cruising sailor is going to depend largely on the conditions in which it will be used. For example, a heavy Maine coastal fog is going to push the scale clearly toward thermal imaging technology. Fog, after all, blocks your sight, and no matter how much ambient light you have, your visibility is still going to be limited. Water molecules suspended in the air, however, won’t impede the reading of thermal signatures. At the other end of the spectrum, extreme cold encountered during a voyage through the Northwest Passage tilts the scale toward the low-light night-vision devices. In such extreme conditions it’s conceivable that the thermal camera equipment could be subjected to temperatures outside of its designed operating range of minus 25 degrees C (minus 13 F). For most cruisers, this shouldn’t be a problem unless you’re planning a winter at one of the polar ice caps.