Infrared Fish finder

[W.T.A]

I am looking to buy a Infrared fish finder for my boat. I have heard about them but I cant find them any were. Anyone know where I can find one or what brand carrys them? Or am I being fed a line of BS? Thank you.

[The Bait Shop Guy]

Many of the underwater cameras have infra red lights. They're almost useless, because infra red energy doesn't penetrate very far into water. It's probably the LAST thing you'd want to use to detect fish. I think somebody was feeding you a line.

[finaddict]

Fishfinders use sonar which stands for "sound navigation and ranging." An acoustic pulse is sent down through the water. The time for the signal return is measured and converted to a distance. The pulse gets reflected off objects with a different density than water such as the bottom or a fish's swimbladder and show up on the screen.

Infrared is a type of electromagnetic radiation that is slightly longer in wavelength than visible light. This type of radiation is used most often in thermal imaging (you know when they can see the guy as a "hotspot" from a helicopter at night on COPS). I guess if the fish is at a different temperature than its surroundings maybe this could work...but I have never heard that such a technology exists.

Maybe you were thinking about a FLIR camera (forward looking infrared) which is used on vehicles at night to see. They make them for boats but I think they start at about 5 grand. I think I'll stick with my Radar!