Yes a spotlight is almost completely useless on a good day in fog and absolutely detrimental on a bad day of fog, whiting out everything and making visibility considerably worse. IR systems do work in fog slightly better than the naked eye but the heavier the fog the more limited in range the ir system is, it’s Definitly not the end all be all running in fog system. The only system not affected by fog is radar. If you want to run in fog on the regular get better with your radar and chart plotter because those two systems are the most useful and when you become comfortable enough with those two systems you can continue to run in fog just like it’s daytime. Image quality and range on civilian units are directly correlated to one thing and one thing only when it comes to IR and that is money. More money equals more range. The biggest difference in range will be once you move up to 2 and 3 axis stabilized gimbals on mounted systems, that will also be the largest jump in price lol. I have used top of the line flir units on the boats I ran while in the navy and the units we were using cost high 300k. You could also read someone’s lips at night over a mile away, fog still greatly reduced its range. You can get very high quality long range handheld units, but on a boat after you go past a certain magnification it becomes almost impossible to hold the unit steady enough for it to be usable. That’s when fixed gimbal mounted systems start really coming into there own. As someone who has used IR extensively I do think they are a useful tool, and if money were no object the unit I would get would be in the mid 40s price wise but by no means do I think they are any sort of magical fog driving machine and Definitly not a requirement for any boat except for one regularly doing search and rescue operations. Most flir units I have ever seen in yachts just sit there unused. Very few people are comfortable running any vessel in reduced visibility no matter the systems or instruments installed on board. Hell radar is the single most useful piece of equipment in all reduced visibility situations and getting people to learn how to use it is like pulling teeth, depth perception is a NEED when driving a boat, no flir unit gives you depth perception, radar gives you nothing but depth perception. Which while driving how far away from something is, is kinda the most important thing you need to know. Needing to know How far, how wide, and how fast something is comes first in what I need to know before identifying what something is. Flir only tells you what it is, radar answers the important questions, unless you have super deep pockets and can afford a mounted gimble unit with laser range finder, auto tracking and target direction and speed identification, they exist but the cost is excessive, honestly don’t know if they are sold to civilians though, the units I have seen have some other features I don’t see them wanting sold to just anybody. Btw they are Still not as good as radar for running in reduced visibility.
