Electronics Glossary

By West Advisor Staff, Last updated: 2/27/2018

AquaLink™ is an ACR Electronics brand of PLBs.

AquaQuake™ water draining function on some ICOM radios clears the speaker of water, emitting a vibrating noise, so the audio is less distorted in really wet boating situations.

ATX™ is Raymarine’s advanced radar target separation technology that displays targets like boats, landmarks, rocks, buoys, and weather cells by improving the resolution of the radar.

Auto Guidance 3.0 is a Garmin navigation function that instantly searches through relevant charts to create a path specifically designed for the dimensions of your boat and provides a visual path that seeks to avoid low bridges, shallow water and other charted obstructions.

Backlight is selectable on/off illumination that lights both the display and keypad on a chartplotter or other device for enhanced screen viewing at night or in low light.

Beam Sharpening is a technique used in Navico’s Broadband G4 and Halo™ radars to increase the resolution of the radar image, separating close-together targets that would otherwise appear incorrectly as one return.

Bearing (BRG) is the precise compass direction (in degrees) from your present position to the next waypoint (in either degrees magnetic or true north).

BlueChart® g2 HD detailed Garmin nautical charts provide port plans, depth contours, navigational aids, and tides and currents in a seamless chart presentation. One-foot HD contours provide a more accurate depiction of bottom structure for improved fishing charts and navigation in swamps, canals and port plans.

Broadband Sonar is Navico’s name for traditional, fixed frequency pulsed sonar.

Category I EPIRBs automatically deploy the beacon when submerged between 3' and 14'.

Category II EPIRBs are manually deployed and activated.

CHIRP DownVision™ is Raymarine’s scanning sonar that delivers a photo like view of the world beneath your boat, allowing you to image bottom structure with amazing detail and target fish simultaneously.

CHIRP Pulse Compression radar technology identifies small, weak targets, even when positioned close to strong returns. See our West Advisor, A New Wave of Marine Radar.

CHIRP scanning sonar creates picture-like underwater images, using high frequencies, enhanced with CHIRP (Compressed High-Intensity Radiated Pulse) technology.

CHIRP sonar transmits a longer pulse than traditional sonar, putting more energy into the water column. See our West Advisor, What’s CHIRP Sonar?

Clear Voice Boost automatically adjusts the outgoing voice and the incoming audio of an Icom VHF radio to compensate for the ambient noise level.

Clear Voice Noise Reduction Technology, used by Standard Horizon VHF radios, eliminates unwanted background noises like engines and wind during transmission.

ClearVü is Garmin’s down-looking scanning sonar that gives you a nearly photographic sonar view of structure and fish that pass below your boat.

Coaxial cable connects your VHF radio with an antenna. See our West Advisor on Coaxial Cable.

Course Over Ground (COG) is the current direction (in degrees) that you are actually traveling (selectable in degrees magnetic or true north).

Cross Track Error (XTE) is a digital reading on GPS steering screens that indicates precisely how far off you are, to the right or left of the center of the course.

dB rating (or antenna gain) indicates the apparent increase in transmitting power due to an antenna’s ability to focus energy. See our West Advisor, Selecting a VHF Antenna.

Digital Selective Calling: All fixed mount VHF radios sold in the US are required to comply with Class D Digital Selective Calling standards. They are part of the international protocol of safety procedures in the Global Maritime Distress Safety System (GMDSS). DSC provides handy non-emergency functions. You need to register your radio and obtain an MMSI Number for these features to work! See our West Advisors, Selecting a Fixed Mount VHF Radio and Enabling Your VHF Radio’s Safety Features.

Distance To Go (DTG) is a digital readout (selectable in miles, nautical miles, or kilometers) displayed only when navigating to a waypoint. It simply indicates the remaining distance from your present position to the next waypoint.

Dot matrix displays are miniature versions of LCD screens seen on TVs, smartphones and other devices. They display any monochrome pattern of dark and light elements, make choosing functions simpler, and allow rounder, more lifelike and readable numerals.

DownScan Imaging is Navico’s down-looking scanning sonar that creates a picture-like view of what’s below your boat, with high frequency 455 or 800kHz imaging technology.

DTM is an abbreviation for Distance To Mark.

DTW is an abbreviation for Distance To Waypoint.

Dual Watch or TriWatch allows you to monitor a working channel, like VHF Channel 72, and Channel 16. TriWatch adds VHF Channel 9.

Dynamic Auto Gain is a Garmin radar function that automatically adjusts gain levels to optimum settings for harbors, near shore and offshore in open waters.

Dynamic Sea Filter is a Garmin radar function that automatically adjusts radar gain to calm, medium and rough sea conditions.

Dynamic Tides and Currents, a feature of the B&G Zeus2 Series, shows tides and currents with a gauge and an arrow instead of the diamond icons used for static tides and current information.

EchoMAP CHIRP chartplotter/sonar combos use high wide CHIRP sonar and Garmin CHIRP SideVü and CHIRP DownVü scanning sonar.

EGNOS: European Geostationary Navigation Overlay Service (EGNOS) is a Satellite Based Augmentation System, very similar to WAAS but supplying correction data to Europe.

Elements: there are three main styles of VHF antenna electrical elements, cut lengths of coax cable, a simple brass radiator, and a more complicated copper and brass radiator.

EPIRBs (Emergency Position Indicator Radio Beacons) are emergency beacons linking your boat to a global government-run emergency network (Cospas-Sarsat), used worldwide to alert Search and Rescue agencies in the event of a dire emergency. See our West Advisor, Selecting an Emergency Beacon.

Evolution is Raymarine’s new line of autopilots that are simple to install and use.

Fantom™ Pulse Compression Radar is Garmin’s solid-state, open-array radar with MotionScope™ technology.

Fishing HotSpots PRO is a series of digital mapping products compatible with selected Lowrance, Simrad and B&G displays. Fishing Hot Spots also makes paper fishing charts.

Float ‘N Flash lets you know where your floating Icom handheld VHF radio is if you drop it overboard, with the flashing red LED light and LCD/key backlight.

ForwardScan® is Simrad’s thru-hull transducer that creates a forward-looking, two-dimensional view of what’s ahead, and helps you avoid running aground.

FrontVü is Garmin’s new forward-scanning sonar that shows submerged obstructions as you approach them within a 300' forward range and helps you avoid collisions.

Galileo is a global navigation system that is currently under development by the European Union, it currently has four satellites orbiting and aims to have full global coverage by 2019.

Garmin Helm™ allows you to view and control your compatible GPSMAP® Series combos or chartplotters from an iPhone® or iPad®, or a phone or tablet using Android™.

GHP Reactor™ is the name for Garmin’s autopilot series that holds your course even when your boat is pitching and rolling in rough water.

GlobalFix™ is ACR Electronics’ brand of EPIRBs.

Global Positioning System (GPS) is a “constellation” of satellites that orbit the Earth and make it possible for people with ground receivers to pinpoint their geographic location. GPS location accuracy is within 10 meters. Location accuracy can be boosted through the use of Wide Area Augmentation System (WAAS) or Differential GPS (DGPS). The GPS is owned and operated by the U.S. Department of Defense but is available for general use around the world.

GLONASS or Global Navigation Satellite System is a global system, which complements GPS and is the only other system that can be used across the world. It is comprised of 24 satellites and is a Russian-based service.

GoFree™ is Navico’s new brand that allows you to download and update charts, software updates and apps direct to your chartplotter or multifunction display.

GRIB weather refers to Gridded binary (GRIB) files, which are the raw data files used by meteorologists to predict weather, available for download from various weather service suppliers.

Halo™ Radar is Simrad’s new 72nm solid state open array radar, with CHIRP and pulse compression technology.

HEROiC is the name of Simrad’s user interface, optimized for widescreen monitors and multi-touch gesture control.

HotMaps Premium is a Navionics premium mapping program, covering inland lakes and made for fishing, that has been discontinued as of January 2016 and replaced by Navionics+.

Insight Genesis is a Navico mapping system that lets you create your own underwater charts. For more info, see our West Advisor, Make Your Own Sonar Maps.

Jeppessen C-Map Max-N is a mapping series from C-Map compatible with selected Lowrance, Simrad and B&G displays.

Lake Insight is a mapping series from Lowrance, available in HD and Pro versions, that covers US inland lakes with underwater detail showing 1’ to 3’ depth contours.

LakeVü HD, Garmin’s highly detailed freshwater maps include 17,000+ U.S. lakes, rivers and reservoirs. That number also includes more than 6,700 HD lakes with 1-foot contours shoreline to shoreline.

Last Call Voice Recording, a function of some Icom VHF radios, automatically saves the last two minutes of the last incoming call. You can replay the received call, and not miss any incoming call.

Laylines are a straight line, or bearing, which extends from a mark or waypoint to indicate the course a boat should sail with one tack to pass to the windward side of the mark.

LightHouse II is the operating system for Raymarine multifunction displays.

Loud Hailer is an intercom/public address device, either a standalone product like the Standard VLH-3000, or as a function included with high-end VHF radios. Often includes a group of pre-programmed foghorn signals with horns, bells and whistles.

Magnetic North is the location our compasses point to; it lies several hundred miles to the south of true north, at a location in Canada.

Map Datums: Since the earth is not flat, a method must be used to create a “flat map” from a round earth. Maps and charts are based on a survey of the area that’s covered by the map or chart. These surveys are called “Datums”. Maps that are created using different datums will show the same latitude/longitude in slightly different locations. Different datums are based on different mathematical models of the earth’s shape and dimensions (ellipsoids) plus an additional factor of projection.

MARPA Target Tracking: Mini-automatic radar plotting aid (MARPA) tracks up to 10 selected targets, helping you keep track of other vessels and avoid collisions.

Memory Scan allows you to scan all channels saved in your VHF radio’s memory.

MMSI or Maritime Mobile Service Identity numbers are issued by BoatUS, SeaTow, US Power Squadrons for free, are sort of a digital telephone number, and are required to make your VHF radio’s DSC functions work properly. See our West Advisor, Enabling Your VHF Radio’s Safety Features.

MotionScope™ Technology, used in the Garmin Fantom™ Radar, uses the Doppler effect to detect and highlight moving targets to help avoid collisions, find flocks of birds and track weather.

Nautic Insight is a mapping series from Lowrance, available in HD and Pro versions, offering coastal mapping.

Navico: Parent company of Lowrance, Simrad, B&G and GoFree electronics manufacturers.

Navionics Gold is a premium mapping program, discontinued as of January 2016, and replaced by Navionics+

Navionics SonarChart™ is an HD bathymetry map series featuring extraordinary bottom contour detail, great for increasing awareness of shallow waters and for locating fishing areas at any depth level.

NMEA 2000 connectivity allows the radio to network with newer electronic devices built to the NMEA 2000 networking standard set by a consortium of the major marine electronics manufactures.

Noise is visual “clutter” that appears on the display. It’s caused by too many undesirable signals being picked up by the fishfinder, typically from electrical sources such as trolling motors, alternators, spark plugs, radio transmitters, etc.

Output Power is the amount of electrical energy applied to the transducer by the sonar transmitter. Expressed in watts, calculated either by the peak-to-peak or root mean squared (RMS) methods. West Marine always shows output in RMS watts.

Panoptix LiveVü Forward is a Garmin sonar that lets you see fish—or even divers—swimming live under and ahead of your boat with a 100' forward range in real time.

Peak-To-Peak is one method of measuring the output power of a sonar transmitter. This value is a measurement of the total swing of an AC voltage from its peak negative value to its peak positive value.

PLBs (Personal Locator Beacons) provide the same worldwide coverage as EPIRBs, but for a person, not a boat, and can rescue hikers, kayakers, backpackers, climbers, pilots, river rafters and hunters (among others) as well as boaters.

Power Boost Key quickly boosts your West Marine handheld VHF radio to the high 6-watt power setting

Priority Scan or Tag Scan allows you to select any number or combination of channels to monitor.

Programmable Scan allows you to scan a user-programmed list of VHF channels.

Pulse Expansion provides the ability to increase the duration of the transmit pulse, which helps maximize the energy on targets. This provides larger target size on the chartplotter. See our West Advisor, A New Wave of Marine Radar.

Quantum™ Wireless CHIRP Radar is Raymarine’s next generation of marine dome radar featuring CHIRP pulse compression technology.

Quickdraw™ Contours is Garmin’s mapping software that instantly creates your own personalized HD fishing maps on screen with one-foot contours.

ResQLink is an ACR Electronics brand of PLBs.

RMS: Literally “root mean squared.” A method of measuring the output power of a sonar transducer. A DC voltage that will produce the same heating effect (power output in watts) as the AC voltage. For a sine wave, the RMS value is equal to 0.707 times the peak value of an AC voltage. Example: divide Peak-to-Peak by two (or in half) and multiple by 0.707 = RMS voltage.

SailSteer is a B&G feature found on Zeus2 and Vulcan chartplotters that combines essential sailing data into one composite screen. Winner of Sail Magazine’s 2014 Pittman Innovation Award.

SailTime, a feature of the B&G Zeus2 series, displays the Time To Waypoint, Distance To Waypoint and Estimated Time or Arrival at waypoint using the layline calculations. This ensures a realistic value for these functions rather than relying on a feature designed for a powerboat.

S.A.M.E. Emergency/Weather Alert, a feature of West Marine VHF radios, allows you to specify the area that you need to hear any alerts that may be Weather, Civil, Biological, Nuclear, or National in nature.

Segmented LCD displays are composed of seven individual elements, and they create the type of chunky, rectangular numerals we’re all familiar with. Each part of the screen, such as the battery life indicator, has segmented components that perform just one function.

SideScan Imaging, used in the Lowrance StructureScan HD module and chartplotter/sonar combos, shows you a picture-like view of what’s to the sides of your boat.

SideVü is Garmin’s side-looking sonar that provides a wide view of what lies off to either side of your boat. An excellent tool for scoping out a fishing area quickly.

SimNet cables and connectors are Navico’s NMEA 2000-compatible networking products. Adapters are required to connect to NMEA 2000 cabling hardware.

Smooth Scaling™ graphics used in Garmin sonar provide uninterrupted imagery when switching between depth-range scales.

SonicHub2 is a Lowrance entertainment module that has an integrated AM/FM antenna, SiriusXM radio connectivity, supports playback from a USB-connected device, and allows you to stream music including Pandora from a smartphone or tablet.

Speed Over Ground (SOG) is a digital reading that indicates your current ground speed (usually selectable in miles-per-hour, knots, or kilometers-per-hour).

StructureScan® HD is a Lowrance sonar module that combines high-frequency DownScan and SideScan sonar imaging technologies to create a picture-like view.

StructureScan® 3D imaging, from Lowrance, scans underwater terrain and fish-holding structure to create a high-resolution, 180-degree, three-dimensional view beneath your vessel.

Thermocline refers to areas underwater where warmer layers of water meet cooler layers, and where fish are often active. Generally, baitfish hang just above the thermocline, while larger game fish are found suspended in or just below it.

TotalScan™ Transducer, from Navico, combines traditional Broadband Sounder™ and CHIRP sonar with SideScan and DownScan Imaging™.

TouchSensible is Simrad’s operating system, a combination of control via a multi-touch screen and keypad/rotary dial for intuitive and precise control in all conditions.

Track (TRK) is a historical representation of the direction you are traveling, shown on the screen of a navigational device.

Trackback is a Lowrance sonar function that lets you scroll back to review multiple pages of sonar history.

TrackYourBuddy is a Navico VHF radio function. Many VHF radios with DSC let you create a buddy list to store the names and associated MMSIs of favorite people. Track Your Buddy allows you to see the locations of folks on your buddy list.

Transducer is the underwater component of the fishfinder that functions like an antenna to send out sonar signals (sound waves) and receive return echoes that are displayed as pictures on the sonar screen.

TripIntel™ technology, featured in Simrad’s GO Series and designed for powerboaters, tracks and displays the key information you need to plan safe and enjoyable days on the water, such as fuel ranges.

Triple Watch Plus™ allows you to monitor emergency channel 16 and 9, another user selectable channel plus weather alert. A function of West Marine VHF radios.

True north is the top of the world, where all lines of longitude converge; not to be confused with magnetic north.

UTC is Coordinated Universal Time. Time at the prime meridian at Greenwich, England. Formerly known as GMT.

Velocity Made Good (VMG) is a digital speed reading, similar to Speed Over Ground (SOG), that compensates for progress being made toward a waypoint. For example, when traveling directly on course toward a waypoint, the SOG and VMG readings may match. However, when traveling off course, the VMG reading will typically be slower than the SOG. VMG is a true indication of the speed being made to the selected waypoint.

Virtual Rudder Feedback is a Lowrance autopilot function that allows outboard-powered boats to not use a rudder-position sensor, simplifying the autopilot installation process.

WAAS: Wide Area Augmentation System (WAAS) is a satellite based augmentation system, more simply described as an “add-on” to the GPS system developed to improve accuracy and availability. WAAS covers the US.

Waypoint is a location, spot, or destination (latitude/longitude) that can be stored in memory to be recalled and used at a later time for navigation purposes. Simply think of it as an electronic address.

Weather Alert, when activated on a VHF radio, notifies the user of inclement conditions by NOAA weather signal.

WebWatch™ is a Shakespeare antenna that lets you access the Internet from a Wi-Fi hotspot or cellular network with up to 4G speeds and share it wirelessly through the built-in hotspot or, through Ethernet.

Wi-Fi allows computers, smartphones, or other devices to connect to the Internet or communicate with one another wirelessly within a particular area.

WiFi-1 WebWhip, a Shakespeare long-range Wi-Fi receiver, increases the coverage of public hotspots. Accesses the Internet directly through LAN or wirelessly, by connecting to any standard Wi-Fi router.

WI-FISH Wi-Fi CHIRP DownVision™ Sonar is a black box sonar module for smartphone and tablets transforms your smartphone into a powerful CHIRP DownVision sonar HybridTouch.

WindPlot is an onscreen presentation of wind history that is a feature of Zeus2 chartplotters designed to help you understand recent changes in wind speed and direction.