[PUP] FLIR and Nauticomp display

Wed Sep 5 12:16:20 EDT 2007

Just a clarification... the most popular FLIR device on boats, made  
by FLIR Systems, is the Mariner model. They've sold tons of them in  
the last two years, mostly on new boats.

Its a swivel, pan, tilt camera that displays composite video on a  
monitor in the boat. Costs about $7000. I installed one on my  
Nordhavn 55, but in my view, it's completely misnamed -- Forward  
Looking Infrared Radar. The manufacturer also says it sees through  
smoke and fog "just like the military ones".  As we've heard here,  
the military units don't do that well.

I say its misnamed because radar units emit a signal that is  
reflected from the target. The Mariner FLIR is completely passive,  
consisting of an uncooled microbolometer that 'sees' in 8-14 um  
wavelength range. Just a camera.

It is not 'fog penetrating' in my experience.

I have found that it will image very well under conditions where you  
could normally see with your naked eye, except for the lack of light.  
What I mean by that, is that on relatively clear but very dark night,  
it will provide a short range picture similar (except for being in  
black and white) to what you eye would see in normal daylight. Great  
for finding your way to a slip in an unfamiliar marina (even reading  
the signs on the end of the docks) or coming into a dark anchorage.  
Navigating in a channel is greatly facilitated as well... you can see  
the unlighted markers.  You can also see waves as they reach your  
boat on a dark, stormy night. Not in time to react to a wave, but to  
build a 'visual reference' to what you'd see in the daytime. Crab  
pots or logs are visible far enough out to avoid if you are moving  
below 5 knots when the water is calm (and someone has their eye glued  
to the screen. Reaction time is minimal). People in a kayak at night  
would be very visible, etc.

Or watching your neighbors on other boats in the marina when they  
think they are covered by darkness. Good for security or maybe seeing  
some things you shouldn't be seeing. (But I digress).

The drawback is that the brightly glowing black and white screen  
wipes out your night vision, so you become dependent on the FLIR once  
you start using it. Normal lights become harder to see. But with a 1)  
good radar, 2) Nobeltec (or similar with the right charts) eNav, and  
3) a FLIR camera, those of us with weakened night vision can operate  
at night, never looking out the window.

Whether that is good boating practice is another thing.  Frankly, I  
avoid night operations in restricted navigation areas. But if I can't  
avoid, this trio of electronic gadgets does make up for my not being  
able to see very well with nature's eyeballs on a dark night.

John Marshall
N5520-Serendipity

On Sep 5, 2007, at 4:40 AM, Mike & Denise wrote:

> Hey Ken,
>
> I'm a newcomer here but I do have a fair amount of experience with  
> thermal
> imaging devices having been a Bradley Fighting Vehicle gunner. My  
> experience
> is that thermals don't work in thick fog or smoke. When you think  
> about how
> they work, that shouldn't be too surprising. They are looking for heat
> contrasts. If you throw a great big wet blanket over everything  
> (fog), you
> do two things. First, you cool the surface of whatever maybe out  
> there.
> Second, you obscure whatever is out there with cold particles. With  
> smoke
> it's a little different, but that shouldn't be encountered much on  
> the water
> so I won't go into it.
>
> I don't have a lot of experience with Forward Looking InfraRed  
> (FLIR) except
> as it is used on some personal night vision devices. But, I would  
> say, based
> on my understanding of how it works, that FLIR would work worse in  
> obscuring
> visibilities (fog, smoke, rain and snow) than thermal. This is  
> because the
> Infrared part is a beam that is shot out ahead of you allowing the  
> device to
> "see" what is illuminated. Infrared is not in the visible spectrum of
> course, so you don't see the beam of infrared light that is being  
> projected.
> So, if you shoot the beam of infrared light into thick fog, you get  
> the same
> thing as you get if you turned on your spot light (only you paid  
> more for
> it).
>
> My experience with night vision devices is that they work well when  
> it is
> just dark. When you throw in other obstructions like rain or fog, then
> thermals are your best bet. When that degrades, you're out of luck.  
> People
> with more FLIR experience may have better info on that subject.
>
> Mike
>
> -----Original Message-----
> From: passagemaking-under-power-bounces at lists.samurai.com
> [mailto:passagemaking-under-power-bounces at lists.samurai.com] On  
> Behalf Of
> Ken Williams
> Sent: Tuesday, September 04, 2007 5:07 PM
> To: 'Passagemaking Under Power List'
> Cc: NordhavnOwners at yahoogroups.com
> Subject: Re: [PUP] FLIR and Nauticomp display
>
> John Ford:
>
> No idea if I'm the Ken you referred to, but your timing is perfect.  
> I'm
> sitting at anchor in the San Juans and had fog so thick this morning I
> couldn't see my own tender. I have a night vision camera with two  
> different
> night modes, "Ultra Low Light", and "thermal imaging".
>
> Both modes were completely useless. There were six boats anchored  
> about 100
> yards away, as well as land perhaps 200 yards away. Nothing showed up,
> including the bow of my own boat.
>
> I've alerted the manufacturer (NVTI) that I am very disappointed in  
> my unit
> (the NVTi 5000). The image in a marina on a clear night isn't bad,  
> but in
> real world conditions, I have yet to find it useful. To be fair: It  
> is going
> back for service and perhaps when I get it back I will be more  
> impressed.
>
> -Ken Williams
> Nordhavn68.com, Sans Souci
>
> -----Original Message-----
> From: passagemaking-under-power-bounces at lists.samurai.com
> [mailto:passagemaking-under-power-bounces at lists.samurai.com] On  
> Behalf Of
> John Ford
> Sent: Tuesday, September 04, 2007 1:42 PM
> To: Passagemaking Under Power List
> Cc: NordhavnOwners at yahoogroups.com
> Subject: Re: [PUP] FLIR and Nauticomp display
>
> On Sep 1, 2007, at 10:23 PM, Scott Bulger wrote:
>
>> FOG shuts it down completely.  I couldn't see past the bow rail.
>
> Thats interesting..  I was hoping that this wouldn't be the case at
> all.  When doing some research and reading many websites one of the
> things they touted was the ability to see in fog.  I would be
> interested in hearing if others "Ken?" have had similar issues with
> the FLIR.
>
> John Ford
> KK44 Feisty Lady(She may turn into a 48 soon).
> Annapolis City Marina
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