Wars are often the cradle of new technology, and hopefully there will later be applications of peaceful use for the human kind. Navigation equipment and Radio telephones are examples of this, and so are sonars and echo sounders. It is hard to imagine, if at all possible, how modern deep sea trawling could take place without such equipment, and maybe even more difficult to understand if it would be possible to catch large quantities of fish at costs making it affordable to the average family.

The first primitive generations of such equipment have later been replaced by newer generations and technology, such as satellite positioning, navigation and communication.

The first cable free Catch Control systems were developed by Scanmar Almost 40 years ago, but it was not a result of war time technology, but just as fascinating: The introduction of lap top computers and mobile telephones required small high powered battery cells and components and circuits with low power consumption. This was an important prerequisite for small sensors placed on fishing gear thousands of meters away from the fishing vessel.

 Of course, this was not enough, but it was a necessary prerequisite for developing systems that would be easy to handle and operate for some time without need for recharging.

The real challenge then was to develop reliable hydro acoustic communication link between sensors and vessels, over long distances, under harsh conditions and with noise levels of great variation and strength from vessel to vessel. That was an ongoing process for many, many years, and costed millions and millions of dollars.

Another challenge was to find the optimal way to manufacture the sensors in a way to avoid, or reduce to a minimum, the possibility of damages and leakage to electronics caused by deep sea operations, blows to the sensors hitting the bottom or vessel, but it finally became possible due to development of new plastic and special production methods.

Scanmar systems become widely appreciated and sold all over the world, also resulting in an increased for new information, i.e. new sensors. And already before one decade was passed Trawl Eye, Trawl speed, Symmetry and Grid sensors had been developed, and added to systems already installed in many countries, not only the most advanced fishery nations.

Ten thousands of skippers, first mates, navigators and fisherman have become acquainted with Scanmar systems, and cannot “go to sea without it”, as they say. Many can use the systems very well, but still there are many that are not able to fully take advantage of a complete system, as we will explain.

It is even worse if a system is not complete!

Most people think of a Catch Control system as an instrument to see the amount of catch, depth of the trawl, door distance, fish entrance etc., and of course it is, but it can be so much more, and to many it is:

• Fish’ locations are often given by fear of predators, water temperature, under water currents and amounts of bait available.
• During trawling the trawl and gear, and its performance, is subject to inefficient operation for many different reasons (some being):

-        Vessel speed

-        Warp lengths

-        Wind and waves

-        Seabed conditions

-        Under water currents (speed and directions)

-        Trawl construction

-        Damage to trawl, doors or gear

Like all the rest of us, most fisher men are slave to their habits, and we should all ask ourselves if what we have been doing for ages is the right thing today, and in the future.

I recommend that anybody that has the possibility should watch a Scanmar screen, watch the vessel speed (GPS) and listen to the engine, and wonder if changes in the performance and catch may be due to change of course and speed, and especially strengths and directions of possible under water currents.

Rigging that is not 100 %, small damages to doors, gear and trawl, or just plain wear and tear, may also cause some reduction in efficiency. By just watching speed and angle information and relate it to door spread and trawl opening, very much may be achieved just by small adjustments.

Any questions?

Please ask!