<h2>The Technical Background</h2>
<p>All fishfinders work on the same principle: they continuously emit <strong>sound waves</strong> - so-called pings. These sound waves travel through water at 1,500 metres per second. When they strike an object, a living creature or the bottom, they produce echoes that appear as an image on the <strong>fishfinder display</strong>.</p>
<h2>Applications and General Functions</h2>
<p>A modern fishfinder does far more than just show you the depth - it makes the <strong>invisible</strong> visible. With a little practice you can read quite precisely what is going on beneath the boat. That includes identifying the profile structure of a water, recognising vegetation and bottom composition, finding shallows and drop-offs, locating submerged objects and obstacles, and of course pinpointing <strong>individual fish</strong> and <strong>shoals</strong>.</p>
<p>This increases your effectiveness many times over and your chances of a catch will rise dramatically.</p>
<h3>The 2D Image</h3>
<p>Every fishfinder has a 2D view. This <strong>standard view</strong> gives you all the information you need to understand what is happening directly beneath the boat. Most units today are equipped with <strong>colour displays</strong> that already separate detail very well through their colour gradients. Bottom hardness, for example, is visible from the colour, and fish stand out clearly from other objects.</p>
<h3>Photo-Realistic 2D Images</h3>
<p>An excellent development of the 2D view is Down Imaging - known as Di+ by <em>Humminbird</em> or Clearvü by <em>Garmin</em>. The image is photo-realistic, giving you tremendous <strong>detail sharpness</strong> - down to individual strands of weed, small branches and, in ideal conditions, even the body shape and fins of fish. You can say with <strong>100%</strong> certainty which species is currently sitting beneath your boat or what kind of snag your lure keeps getting caught on.</p>
<h3>The Side View</h3>
<p>Another powerful fishfinder function is Side Imaging - Si+ with <em>Humminbird</em> or Sidevü with <em>Garmin</em>. For the first time it lets you scan the <strong>water areas</strong> to the left and right of your boat so that nothing slips past unnoticed. With a little practice you can read the shadows instantly and understand what you are looking at. Even fish are <strong>shown clearly</strong> and can be cast to without difficulty. It is a superb technique for covering large areas of water in a short time.</p>
<h3>Depth Maps and GPS</h3>
<p>Many fishfinders also offer practical features such as the automatic creation of depth maps, which record the <strong>depth zones</strong> of a water and gradually build up a complete chart for you to navigate by in the future. Once the map is complete, <strong>waypoints</strong> can be set via GPS, allowing you to save your own routes and follow them automatically with a compatible motor. Productive <strong>hotspots</strong> can be relocated to the metre even in rough conditions, and time spent searching unnecessarily becomes a thing of the past.</p>
<p>These are the most important and most interesting functions, briefly explained - in the individual product listings we go deeper into each unit and describe its functions in full detail.</p>
