Amazing Side Imaging Tool – view your sonar images in Google Earth

I have been using  a Humminbird Side Imaging Unit (987) on the kayak for a few years now. The unit has produced some great results when out on the water kayak fishing.

It enables me to scan the seabed (and the water column) for over 200 feet either side of the kayak. It picks up alot of detail…

But, the really clever stuff takes place at home. The unit has 2 card slots. One contains a Navionics Gold SD card which holds the marine charts for the areas I fish…

The other slot contains a blank SD card which I use to record the raw side imaging sonar data. When I get home, I take out the SD card and copy this data to my PC.

I have been using a few software packages to display and manipulate this data in various ways , and I have been getting some good results…

And this is great for viewing single recordings of trips.

But what I have really been after, is a way by which I could display all of my recordings simultaneously in Google Earth. That way you could build up a 3D picture of the sea bed where you fish and view all of your footage in one go.

Well, it seems that my prayers have been answered; I had been enquiring about the possibility of something like this on a few side imaging forums, and I came across a product called Sonar TRX. I have been testing out early versions of the application, and it has produced some amazing results – and I suspect that I have only really scratched the surface so far.

Sonar TRX lets you load in data tracks recorded from Humminbird Side Imaging Fishfinders (and now Lowrance side structure models too) and then processes them into a format that Google Earth can display. The clever thing is that Google Earth can be used to display multiple tracks – so you can soon build up an incredibly detailed picture of quite a wide area.

There are loads of options you can set to see more or less detail in the tiles when you display them in Google Earth.

I live near the coast of the Bristol Channel in the UK. This has the second highest tidal range in the world – 15 meters (thats over 45 feet !). Now luckily, the arial images which Google Earth uses on that stretch of the coastline were taken at low tide. This means that you can see the exposed reefs, some of which you fish over at high water. So it provided a unique opportunity to gather some side imaging data when kayak fishing and see how accurately it really was when superimposed over the top of the real Google Earth images.

This is what I have come up with so far…

You can see that the real Google Earth arial images and the 4 side imaging recordings converted by Sonar TRX match almost exactly.

So then I started to explore the seabed beyond the low water mark, and the results were just as amazing…


You can clearly see the edges of the reefs and the darker mud in between them in the image above.


The possibilities offered by this piece of software are breathtaking – this is technology, which only a few years ago would have cost tens of thousands of pounds and would probably only have been available to the offshore oil industry/survey vessels. Now its being used by Dizzyfish in his fishing Kayak !