Grayscale, Inverse: Inverse Grayscale is a Humminbird® feature that reverses the correlation of sonar signal strength and the sha de of gray ty pically used to represent it . The st rongest sonar sig nals a re represented by “white“, and progressively weaker signals are represented in progressively darker shades of gray. While somewhat counter-intuitive, this method ma kes the sonar images crisper, and has the benefit of enhancing the apparent sensitivity because the weaker signals appear bolder. Inverse grayscale works well in very clear water. Debris-laden water often appears as a lot of clutter on the screen.

Instant I mage Up date: Instant Image Up date is a H umminbird® feature that updates all the sonar information on the display when Sensitivity and a variety of sonar settings ( Bottom View, Range, e tc.) are modified. This differs from the traditional functionality that onl y updates the n ew sonar information collected after the setting change. Instant Image Update permits more accurate fine-tuning of the display because the user can see the results on the complete sonar graph. When co mbined with the F reeze Frame f eature, the user c an adjust and understand the effects of many different sonar settings quicklyand easily.

Maximum Depth Menu: The Maximum Depth Menu is a H umminbird® feature that optimizes performance based on the maximum operational depth set by the user. Many Humminbird® units can operate across a very broad depth range (up to 2500 feet) which causes the unit to “ look“ up to that full depth under some circumstances. Due t o the spee d of sou nd in water, th is can resul t i n l ess responsiveness because the unit hasto wait for a longer period of time to receive the sonar signal. When the Maximum Depth menu is set toa lower value, the unit only looks up to the setting, which increases the responsiveness of the unit. This is an important feature for anyoneoperating in shallower depths!

Noise: Noise is unintentional,externalsound waves that interfere with the optimal operation of sonar. Noise appearsas random “dots“ on the display, and is caused by a variety of sources. Electrical noise (from trolling motors, bilge pumps, VHF radios) typically m anifests as a consiste nt dot p attern. Electrical noise c an be isolated by selectively turning on and off other electrical devices to determine the source. Often re-routing the power cable, or connecting to an alternative power supply (second battery) can help overcome electrical noise. Hydrodynamic noise (from propeller a nd/or hull cavitation) has a mo re random a ppearanceand is generally related to boat s peed, so that fa ster operationresults in more noise. Hydrodynamic noise can be overcome by proper transducer installation. Many

Glossary

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