Experiences with FLIR cams?

Under ideal conditions they are great. In non ideal conditions they are disappointing. We put one one a yacht I was working on eight years ago for the purpose of picking up pongas off Central America that would drift and sleep at night without any lights. Couldn't pick out any, earlier than the naked eye could. When the boat, water and air are very close to the same temperature you can't expect too much from it. Electronics technician in San Diego said the local tuna fleet put them on in order to see birds and were disappointed when they were unable to. In the northwest we were not able to pick up logs or crab pot buoys in the water until its almost too late because again it's temperature is the same as the water temp. No benefit found in fog or rain. Too much refraction from moisture in the air. The only benefit we found in open ocean cruising was that you could see the contour of the water.
Inshore navigation is where it is most beneficial. A little more ambient light and temperature differential of objects makes them stand out a little more. I would still recommend having one if you have the budget and space for it. Any extra tool that may keep you safe and out of trouble is worth it. Just don't expect too much out of them. 90% of your night driving will still be done with naked eye, radar, binoculars, and chart plotter first.

I'd caution all who used them in the past to understand one thing. Wally referred to a yacht he was working on 8 years ago. FLIR for marine applications has come a long way in 8 years. We got our first FLIR in 2014 and we've upgraded it since them, in 2019.

The pics I posted a couple of days again were from a 2009 vintage system. Still picks up markers at 1/4 mile. In a narrow channel, and on an enclosed PH where you may not see the day markers even close, you can be reassured you re going to pass far enough but looking at the spot where the marker falls off the screen.

you don’t FLIR to spot small fishing boats while at cruise. That s what radar is for

The physical principle of an infrared vision sytem is the measurement of the Delta T. Means, no temperature difference with the sensor specs, no detection. The performance of such systems depends on the quality of the IR sensor, mostly a gallium arsenit dector element and the electronics behind it (D / A convertor). For the detection of a Delta T at a fraction of a degree, you will need a cryogenical cooled IR sensor.

If You really want a fully usable forward looking infrared (FLIR) system, you will need a multi sensor system, for example with IR sensor, HR colour daylight camera and low light b&w camera. And this system intergrated into the onbord nav systems like radar, search light and AIS. The system is able to lock on to radar targets, track and focuses on them. The targets detected on radar or AIS can then be identified visually on IR and / or optical cameras by switching between the different sensors.

A single sensor basic low resolution IR system can help navigating in adverse conditions but never as the primary source of navigation. We have the FLIR M500 on one boat and the M400 on the other boat. The regular maintenance intervalls for the M500 cooled sensor are a real pain in the neck (the system has to be removed and send in) but both captains swear on their IR systems and do not want to miss them.

But the gretest IR sensor I have ever had and still have is the FLIR system in my larger jet, with the picture displayed on the pilots head up displays. It gives so much confidence on low visibility or night approaches, that I am sure my pilots would leave me, if I would give them a jet without a FLIR in the future .

Below a comparison between the non cooled M400 and the cooled M500.



The real performance difference gets obvious at larger ranges.

But the longer range is irrelevant for navigation as the boats in this video will show up on radar. For navigation and collision avoidance you don’t see all the details and you certainly don’t want to waste time and attention aiming and zooming in Radar will get you the big picture of all traffic in one snapshot

I took this picture last night to show the limitations of FLIR depending on conditions. Same view as posted before but on a very muggy humid night.

day markers visible at a quarter mile on a dry night are barely visible at 300’

Let me guess: in those conditions, didn't you actually see the marker better by bare eye?
Of course, assuming to not be blinded by any helm lights, no glass reflections, etc.

Actually yes. On the way in, with the lights from the city reflecting on the water, even in an enclosed PH it was visible from a longer distance. On the way out, not so much . That’s why spotlights come in handy once in a while.