Thermal-imaging cameras were once the preserve of the military. Now you can get one that clips to your phone


Being able to see heat, particularly in a man-overboard situation at night, could be a potential lifesaver.

Until recently, thermal-imaging camera systems built for yachts were extremely expensive. Both fixed and portable systems were mainly found on large yachts.

The cameras work by detecting the amount of infrared light entering the lens and then converting this into an image that depicts degrees of heat in varying shades of colour.

Thermal imaging camera FLIR ONE

With these products you’ll also see a ‘Buy Now’ link or widget. If you click on this then we may receive a small amount of money from the retailer if you purchase the item, but this doesn’t affect the amount you pay.

Unlike night-vision technology which enhances the light available, thermal cameras will work in absolute darkness.

The FLIR One fits in the palm of the hand. By using your smartphone as the screen, it’s the most compact thermal-imaging camera we’ve seen and packs away cleverly into a hard protective case that can be kept on a lanyard. However, the FLIR One isn’t waterproof.

Integral to the camera’s functionality is
its app, which makes switching between camera modes easier, allowing you to save images to your smartphone, potentially
useful when being used as an engineering tool.

Despite having its own power supply, charged using a micro USB port, the battery drains relatively quickly.


We used the FLIR One iPhone model (it’s
 also available for Android) in a variety of situations afloat.

In the engine room, the camera clearly differentiated between varying degrees of heat and can identify moisture or electrical issues, while outside on a cold winter evening, it was brilliant at showing up humans and animals in pitch darkness.

Pointing the camera at someone wearing a heavy winter jacket showed exactly where the heat was leaking. An MOB would stand out clearly 
in the water, even at some distance.


A neat, versatile piece of kit for any size of yacht. We were impressed by the quality of the picture generated from such a small camera, though it is compromised by a delicate connection plugging directly into the iPhone.

This also means that if you keep your phone in a waterproof case, it has to come out.

A person shown usinga thermal imaging camera

It’s not an essential piece of kit, but it’s certainly
a well-priced, clever addition to your boat’s engineering arsenal that could come into
its own as an additional MOB search tool
or finding your way into a dark anchorage.

An upgraded model, the FLIR One Pro, is also available. Flir One iPhone model £220.


FLIR Ocean Scout £550

A thermal imaging camera for yachtsman

A thermal camera aimed at yachtsmen wanting a thermal imaging monocular to keep at hand. Incorporating an alert mode that automatically identifies the hottest object in view, it’s capable of generating a clear picture in total darkness.

Seek Thermal Imaging Camera for Android £190.80

The Seek offers a similar product to the FLIR One, but doesn’t need to be charged separately, relying instead on the smartphone’s power supply.

It’s also available in a pro model, which offers higher resolution and a wider field of view than the standard model.

FLIR M232 Thermal IP Camera £2,999

Marketed as an affordable thermal camera for fixed installation, the M232 can be mounted on the spreaders, giving the helmsman a much greater degree of situational awareness.

It also incorporates pan and tilt technology to ensure the camera angle can be adjusted remotely.