Searching for wrecks with side scan sonar


While I’m waiting to get my pre-ordered Trident, I have bought a side scan sonar and mounted it on my Hobie (sit-on-top) kayak and started to search for wrecks and other strange formations etc. on the bottom of the sea. And last Sunday I actually found a ship wreck, and thought that should share the pics with anyone interested.

I would also like to know if anyone else here uses side scan sonar, and if so, what brand/model?

And if you laugh at the word “fart” in the pictures, it means “speed” in Swedish ::smiley:

Recommended topside side scan sonar systems

1st off @Peter_S well done for going out and looking for wreck

I have been searching for shipwrecks for a few years so over the time have built up a few nice toys

I have a few Klein 595 Side scan units that have been converted for digital operations as well as a Klein 2000 complete digital unit

I also have a WASSP S3 Multibeam

I also know that @Walt_Holm uses a Starfish unit and @Kevin_K has a Deepvision system it would be interesting to see who else is playing with what



Thanks Scott! The place where I live is actually one of the most ship wreck cluttered areas in Europe, due to that there are over 6,500 islands in our archipelago, and it has been a trade route for ships since before the viking era. Our island is right between Stockholm and Helsinki and on the way to Moscow, so most the ships that went trough the Baltic sea to Russia have passed by here.

They have actually found a wreck here that contained hundreds of old Champagne and beer bottles. The Champagne was auctioned off and broke the world record of being the most expensive Champagne in the world :slight_smile: And last summer, some divers found a new wreck with more bottles that they are getting a permit for now to investigate.

The only thing that sucks is that everything you find here that is believed to be older than 150 years old automatically belongs to the government, and anything younger than that has to be handed to the “lost and found” department of the local police station.

So the money from the Champagne that got sold in the auction actually went to the government, not to the divers who found it :frowning:

But still it is very interesting, and a very good place to live when the Trident is delivered :wink:

It seems like you have a lot of cool gadgets, and I bet you get really good images with those? Do you have any images of wrecks that you might share?

I only have a very cheap side scan sonar (Humminbird Helix 5 si), but since I only have a kayak I really can’t drag along those heavy duty scanners :stuck_out_tongue:


What scale is it? The “Left 40” and “Right 40” would indicate that the wreck is about 40 meters long… and yet your depth is 2,8 meters… or am I missing something?

I’ve just bought a Garmin side scan and mounted on my Ockelbo B16AL… Also in preparation for the arrival of the Trident. The process will hopefully be

  1. Find interesting echo on the side scan.
  2. Send down the Trident to have a closer look.
  3. Dive the wreck and if there is something good there and it’s younger than 100 years (not 150 as far as I know), buy it from the insurance company and salvage the goods. If it’s older or not valuable, just enjoy some nice wreckdiving.


To be perfectly honest, I’m not 100% sure of the length of it. The sonar in those pictures shoot out 40 meters to both sides, but then between the two side beams, there is a down scan beam that covers a certain area also. But I have a hard time believing that the wreck is more than 20 meters long. The water there is also very murky/muddy, so you can’t see anything from the surface.

But I will try to play around a bit more with the sonar as soon as I have time, and then I might be able to figure out how to measure things that show up in it. And hopefully Trident will also help out a lot to get a better view and sense of scale in the water.

It sounds like you pretty much have the same process as me, except for that I won’t do any diving since I don’t have a license. :slight_smile:


Yes I’m well aware of some of the wrecks in the Baltic Sea some really nice dives there (albeit maybe a little cool for us fair weather divers)

Our wreck legislation over here is much stricter basically everything over 75 years old is protected

Some of the images of wreck over here can be seen in the Structure from Motion treads

The last thing I found was just a just a scuttled barge - nothing special - but always good to find something[group-10411]/0/


Congratulations on the find! I use a Humminbird 997. We call it a “poor man’s side scan” since it has such limited range. We have a home made tow fish with a spare transponder on it that we tow when we can. I am working the southwest corner of Michigan so most of our work is near shore in Lake Michigan.


Wow, really cool images and very detailed! Hopefully I can afford equipment like that in the future too :slight_smile:


I am pretty sure Tom Kowalczk has been working his sidescan around that area as well (sorry for vague geography I’m on the other side of the globe so it all seems close from my perspective)


While I was in school we used a EdgeTech 4125 tow sidescan and a Geometric G882 Magnetometer. There is no way I can afford either one of those, but when I brought a used boat it had a Lowrance HSD 8 Gen 1 on it. All I had to do was to buy a LLS Transducer. I have not really used it much to find wrecks, but this summer when the winds calm down I will be out there searching. And that brings me to the Trident. I wonder if a small magnetometer could be attached to the bottom without it interfering or detecting the Trident. I am not a computer or electronic guy.


@Peter_S Welcome to the world of pre-searching before you dump an ROV on something. @Scott_W has the best equipment probably in the community. That WASSP S3 System will find anything and give you exact coordinates.

Off Southern California, my wrecks tend to be deeper and smaller than hull mounted sonars can pick up so I went with a DeepVision DE680D sonar with 200m of cable. It works very well and I am pretty happy with it. The Little Eye LE340 model may be good for you if all you have is a kayak. I have a facebook page for what I scan and find:


Wow, nice pics Peter, ! what is your SSS ? brand and model please. I own a very affordable side scan I bought about 9 years ago. This really is the “poor man’s side scan” hha . Is very limitated but you get from time to time some decent images. Is a transducer working with a Lowrance marine echosounder. It is a single channel. so scans just one side at time. The guy who made them is Garry Burton, I’ve tryied to contact him a lot, lately but no response. even I invited him to join this forum, but no clues. .If someone knows what happend to him. The device is known as Burton M1 side scan.
Here’s a pic, from a wreck in 25 mts deph. I’d already known its location.


Everything is about the early work,

  • You find the wrecks by the research back on shore not by just dumb luck and burning fuel hopping to drive over something.
  • The $'s spent of the equipment doesn’t find the wrecks its the motivation and just getting out there to do the search and the search’s persistence that finds the targets “just get out there and do it and keep doing it”
  • You find the best spots to put the ROV in by knowing what targets are around

Different equipment only give’s you a better chances to find different aspects of potential wrecks with no one technology winning out but in IMHO the best “all rounder” is some form of side scan. The DIY Lowrance and Hummingbird Side imaging units are great and have found a heap of stuff. They would be my 1st jumping off point (albeit I would add a DIY towfish - big and heavy to get it down close to the bottom where Sidescan works best) if I was looking into searching for targets most likly paired with something like Reefmaster

I have used one of those a few years back those are really nice results off the unit. My best guess is that the technology out there with the DIY Lowrance and Hummingbird Side imaging units has overtaken the M1 - But if it works use it (hey my Klein 595’s are now 28 years old and still doing what they do new is not always better)


I strongly suspect you will not be able to do this

A magnetometer is looking for magnetic changes so the motors of the ROV will strongly interfere with the mag for either of the two main marine mags unless you can tow it (say 10m) behind the ROV and both of the main forms use a fair bit of power to operate

or cesium-vapor marine magnetometer


A metal detector mounted on the ROV is a real possibility


Thank you Marco, but I must say that your images are even cooler :sunglasses:

You can see so many details on the ship and just sits there with no debris around what so ever. It’s like it just floating on the surface like nothing happened to it, but the surface is actually the bottom of the sea :slight_smile:

I think I have a lot to learn when it comes to from what angle and distance to drive by the wrecks to get the best images. But that’s where this great community comes in handy. I think there is a lot of gathered knowledge here, and I am happy to learn more from all you guys!


@Peter_S I’d love to see a picture of how you mounted you sonar…especially to a Hobie, that’s amazing!


By the way, my sss is a Humminbird Helix 5 SI (side image) in case you missed it!


Well, you have to do some “MacGyvering”, but it isn’t really too hard to do. If I have some time to spare tomorrow I will take some photos and try to describe everything the best way possible if anyone else want to try to do the same thing :slight_smile:


Here are some photos of the Hobie kayak with the Humminbird Helix 5 SI. The transducer mount is probably not the final version, but still it is something that works for now and that also protects the transducer from rocks etc. I can also pull up the rudder and transducer with a lever if needed.

The only thing is that the image will be a bit distorted if I move the rudder and turn, but then the image will be distorted anyway. And when you have found a wreck and do the scan, you usually go in a straight line to get a good picture.

The holder for the screen I made with some parts that I found on a garage sale, and made use for the hole where you put the mast for the sail, which I never use anyway.

And the battery is somewhat protected from water in a cheap plastic box that I bought and drilled a hole trough for the cable.

There are actually mounts that you can buy and attach to the hull with screws, but I wanted to do minor damage to the hull in case it didn’t work as planned or if I want to change something when I have learned a bit more how it works.


Hi @Peter_S:

Thanks for starting this thread. As others have pointed out, in order to have targets to explore with your ROV, you’re going to need some sort of sonar system to find them.

Last fall I did some playing around with low-cost sidescan systems based upon commercial fishfinders. There are a number of people on the internet who have modified their Humminbird fishfinders by mounting the transducer on a homemade towfish. These kinds of techniques work well out to about 50m of cable length, which covers most shallow-water work.

Here’s a photo of a homemade towfish I put together for a Humminbird system. The fish is made out of PVC tubing and is filled with lead shot to get whatever weighting characteristics you desire. The transducer is a Humminbird HD SI unit:

After doing some tests with this, I wanted better resolution. The best fishfinder sidescan transducer out there is apparently the Lowrance LSS-2, so I 3-D printed a bracket for the transducer to mount directly to PVC tubing:

I did some tests at Lake Tahoe with this new towfish, and performance seemed similar to a Starfish 452…at a tiny fraction of the cost.

In November I started doing some modifications to this fish to extend the cable length out to 50m. I tried an experiment with Blue Robotics tether, but it didn’t work that well, likely because the individual twisted pairs within the cable are not shielded. I’m still looking around for some low-cost cable that has 3 or 4 twisted-shielded pairs, and a Kevlar strength member.