For individuals reading this forum that are interested in obtaining a Side Scan Sonar, there are several ways that this can be accomplished: 1) Renting 2) Build everything

3) Integrate existing pieces and equipment 4) Buy a completed unit.

Before Build or Buy

Operating a Side Scan Sonar (SSS) unit effectively is not the same as reading a depth finder. There are many other factors to consider. Before you think about even starting a project or buying a side scan sonar unit, try to get some exposure to the actual operation of a professional side scan survey. Ask a geophysical company in your area if you can come along on a survey. There are also some individuals that own a side scan unit that may let you come along on a search, a few are good operators, others have no idea what they are doing. Some excellent manufacturers ( Klein Associates) offer several days of training as part of the sale of a side scan unit. It is very important that you get actual experience in the body of water that you intend to search, not just in a classroom or from a book.


CAUTION: the nice sonar images that you see in the manufacturers literature were, most likely, not what appeared when the object was first recognized. It probably looked very different, this is where experience in sonograph recognition becomes very important and is the difference between finding an object and passing it by. The bottom and thermal conditions of a river, lake, or ocean will present a very different set of circumstances depending on their individual characteristics.

Renting:

It may be money well spent to first rent a SSS unit for a few weeks to a month to try it out in your area, before making a big investment of time and money.

Build Everything

This is a very formidable task and will take several years and lots of research and work to construct a side scan sonar. There are several technologies that need to be understood. The critical one is transducer development. Consider that professional SSS manufactures will spend years to develop transducers and side scan sonar systems and that they have a project team working on it. Only attempt this if you have lots of time and can wait several years before you get a SSS operational.

Integrate existing pieces and equipment

For the individual with some technical experience and an interest in building electronics equipment, this can be the best option for putting together a near professional SSS system for a fraction of the cost. There are surplus SSS systems and various graphic recorders that appear from time to time on internet auctions (EBAY and etc.) or that may be available from geophysical companies in your area that are upgrading parts or all of their SSS equipment. To construct SSS system this way, you will need to have at least the knowledge of a good electronic technician and it will more than likely take lots of your time to accomplish integrating these pieces of equipment.


A Simple SSS Project: If you want to just get a taste of side scan sonar, you can build the SSS Towfish project as described at: http://www.portup.com/~dfount/sidescan.htm

Caution: This unit is good for getting a feel for side scan sonar and for locating a wreck when you know approximately where it is. However, from the results that I have seen, it does not come close to what can be achieved with the professional SSS units. When you are ready to spend lots of your time and money on a wreck search effort don’t do it with a marginal system or minimal experience. If you miss the object or wreck because of these reasons you will never find what you are looking for and it will become a very expensive situation.

Buy a completed unit.

There are a number of manufacturers that now offer a variety of side scan sonar units as shown in the list provided by Dan at: http://www.portup.com/~dfount/sidescan.htm#lynx

Individuals and geophysical survey companies may also offer their SSS equipment for sale. Before you buy (see previous comments above) you need to determine what you need for your typical search/ survey effort. Do you want high resolution with limited range, or medium range detection with medium resolution, or long range detection with lower resolution? How will you operate the SSS and what kind of display will be sufficient? Will it be in a small open boat with no cover, a small boat with limited covering, or in a cabin area? Note: Sunlight will wash out most computer display screens. Can you watch a computer screen in a rolling boat 10 to 12 hours per day? Try it for awhile, with a barf bag ready for use!! Do you want a paper print out or store everything on a Hard Drive. Think about how you can review a possible target while you are still in the process of searching. And, the convenience of the post review after the search is over: Note: I prefer paper. How much cable do you need and what is it’s breaking strength? This will depend on the water depth of the survey, survey boat speed, anticipated thermal conditions. A Towfish heavily weighted or one using a depressor will need a cable that has sufficient strength not to break under tow or when it may get caught on the bottom unexpectedly.


CAUTION: When buying any SSS unit you should have an actual demonstration of the unit to assure that it is working properly. This is especially important when buying a used SSS. The SSS unit may appear to be working, but one of the Towfish transducers may be damaged and only partially working, thus limiting the expected range and resolution on one of the channels. Part of your check out should consist of a demonstration on a known object to determine if unit still meets the distance and resolution specifications of the manufacturer.
There are many additional issues to consider than I have time to discuss here. Perhaps other forum members that are experienced Side Scan Sonar builders and operators can add to these suggestions. Perhaps this note will also generate additional build /buy questions for those on the forum that are anticipating acquiring a side scan sonar unit in the future. Best Regards and good luck to all. Jim