Fish Finders - Improving Your Odds

No longer do you need to glance at the screen of your fish finder with that skeptical look that says, “so you’re telling me something’s down there, but my guess is as good as yours what it is.”  Today’s systems incorporate sonar technology that is quite capable and reliable without necessitating a military budget.     

If it's There, You'll Find It

Whereas a simple depth finder sends a beam downward and waits for the return signal, a fish finder can distinguish between different objects.  It accounts for changes in acoustic signature that occur as the signal impacts different matter. 

For instance, fish are detectable because of the air that is stored in their swim bladders.  This pocket of air inside them has a distinct acoustic signature, unlike the flesh of the fish, which is quite similar in density to the surrounding water. 

By this methodology a fish finder can distinguish marine life from coral and other matter.  Some systems can even tell the size of the fish based upon the signal returns. 

Better Fishing Through Technology

Beyond the ability to see downward, there are fish finding systems available today that can see sideways and forward of the boat.  Thus, you can get early warning on depth changes and seafloor topography before you’re right on top of it. 

With such equipment, you have at your disposal a fully effective sonar package that scans the entire underwater area around you. 

Add in an underwater imaging system that uses cameras to give you an actual shot of what the waters look like beneath you, and you're face to face with your prey before you've even cast a line.  

Multiple frequency capability and variable beams allow you to fine tune a scan to compensate for different seafloor characteristics, as well as to focus on specific types of fish that you're hunting.

Nowadays manufacturers are consolidating all the latest technology into one multi-function display that can tell a boater everything about his position and what’s around him.  Depth finding, fish finding, GPS, and chart plotting can all be done on one screen, making it easier to find the breeding grounds, while making it harder to run aground.

Putting a Microphone to the Water

Fish finders are comprised of two components; the transducer and the display unit.  Housed in, or attached to the hull of the boat, the transducer sends out a focused burst of acoustic energy into the water and then receives the signals that reflect off objects below.  From the transducer, the signals are sent up into the display unit on deck that processes the data into a discernible reading.

Transducers can be mounted at three different points on or in the hull of a boat, and can be made of a few different materials.  Fiberglass hulls work best with plastic or bronze transducers.  For wood hulls, bronze is preferable because, unlike plastic, it won’t risk damage in the event of expansion of the hull.  Metal hulls can be equipped with plastic, bronze, or stainless steel transducers.

The mounting of the transducer depends on the type of boat and its propulsion system.  Smaller boats with planing hulls usually feature transom-mounted transducers because of the ease of installation and the fact that they sit forward of the outboard or inboard/outboard engines, preventing interference from aeration. 

Bigger boats with deeper hulls and screws are better off with thru-hull transducers.  The unit sticks out from the bottom of the hull, giving it the best performance of all the mounting positions.  Thru-hulls must be placed such that they are in the water at all times, making them less than ideal for high performance craft.    

Performance oriented boats of fiberglass construction are most suitable for in-hull transducers which are installed inside the hull.  These types can only be used in fiberglass boats, as wood and metal render them completely ineffective. 

The advantage of in-hull systems is that they perform better than the others at high speed.  But because of their mounting, they cannot reach as deep, nor can they detect objects as accurately as the others.

One Device to Rule Them All

With the current trend of consolidating helm systems into one all-purpose display unit,  you need not make more than one purchase in order to outfit your helm with the latest electronics.  Screen sizes vary considerably, as does level of screen detail.  And then there is the choice between monochrome or color.

It's certainly advantageous to own a unit that you don’t have to be right in front of to see, as well as one that is clearly visible in multiple lighting situations.  For about $100 you can get a compact monochrome display that may have a couple of functions. But adding color and navigational systems will cause the price to jump considerably with the high end reaching around $5,000. 

Most would agree, though, that it's money well spent if it can replace all the other electronics you might otherwise have to buy separately.  Not to mention that it takes the guess work out of finding the best fishing spots.   

Getting on the water with the latest fish finding technology won’t guarantee you’ll catch something, but it’ll make the fish wonder how it is you can be so hip to their beat.  Next Step:  Ultra-high frequency fish-behavior manipulators.