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Garmin 540s Review

This Garmin 540s was destined for installation on a 19-foot center console boat used primarily in the waters of the Upper Florida Keys. The boat’s owner was looking for a compact multi-talented unit to replace an antiquated non-operational chartplotter.

Shop for the latest Garmin 540-series chartplotter combos here.

In this configuration the 540s had an internal sounder, internal GPS receiver, and was preloaded with Garmin BlueChart g2 U.S. Coastal cartography covering both coasts, Bahamas, Puerto Rico, Hawaii, Guam, and the Great Lakes.

garmin 540s chartplotter fishfinder combo

Garmin 540s

The 500-series plotters measure 6-inches high by 6.2-inches wide and just under 3-inches deep. They are available in a number of configurations.

All 500-series machines feature a display screen in portrait layout that measures 5-inches on the diagonal and carries either 320 by 240 or 640 by 480 pixel resolution.

Units with a last numeral in the model number of 0 have the lower resolution while those ending with a 5 have the higher.

The small ‘s’ suffix appended to the model number indicates the unit has an internal sounder, high resolution units have a 1000-watt sounder while lower resolution units get a 500-watt sonar.

The center number in the model designation identifies the cartography coverage area, 5 is UK/Australia, 4 is US coastal, 3 is US inland lakes, 2 is base map only.

All 500-series units are capable of using Garmin BlueChart g2 Vision cards.

We flush mounted this Garmin unit using the optional kit. The kit requires a cutout slightly larger than the unit face. Due to the limited space our boat’s panel the kit required some minor modifications to fit, the design lent itself to the easy mod. The flush-mount has a gasket to prevent water intrusion around the unit. Once the flush mount bracket is installed the display unit simply snaps in place.

Power and NMEA 0183 data pass through a single cable that fastened to the case back with a twist lock connector. The additional leg on this cable connected the supplied transom-mount transducer to the display unit.

An optional external GPS sensor can be added if needed or desired and connects to the unit case back using a BNC twist lock. We used the internal antenna for this installation.

Screen Size and Viewability

Our Garmin 540s is equipped with a display screen 3-inches wide and 4-inches high that carried 320 by 240 pixel resolution.

garmin 540s home page

Garmin’s intuitive menu driven software for the 500-series units starts on the Home page.

We rated day viewability on the high resolution Garmin display screen good. We found the screen easy to read even though the unit lacks the fine detail of its higher resolution siblings like the Garmin 545.

When viewed straight on the screen maintains its brightness whether or not the user is wearing polarized sunglasses. At steep side angles we did note a bit of screen darkening. No screen fogging was apparent in the display at anytime.

The Garmin 540s has both a day and night color palette. The night palette darkens the screen colors to enhance low-light viewing.

This unit also has an automatic backlight control system that uses a sensor to vary the screen brightness to match ambient light conditions. We tried it and found it worked very well.


This Garmin chartplotter fishfinder, like all other 500-series units, uses a handful of pushbuttons to manipulate onscreen menus. It all starts on the Home page where the user can select from one of six main pages, Chart, Sonar, Chart/Sonar, Where To, Information, and Configure.

The new owners of this unit found it very intuitive and easy to use commenting that the software never required them to break out the owners manual. They loved it.


garmin 540s split screen

The Garmin 540s split screen showing the chart page above and fishfinder below.

Pushing the Mark button creates a waypoint at vessel’s present position. Once created, you can then edit, delete, select the point as MOB, or go back to the chart page.

You choose a waypoint from the chart page or select one off the waypoint list. Then to begin navigation to the point execute the Navigate To and Go To functions. This puts data boxes up onscreen with course and distance to the waypoint, plus shows a course line to follow on the chart page.

Waypoints are identified with one of 70 symbols and names with up to ten characters. The 540s can store up to 1500 waypoints.


The Information page leads the user through route building. Once there you work your way to the new route page, then simply place the cursor in the desired position and hit Select to create each point along the route. Routes can also be built on the chart page using the cursor pad and Select button. The 540s can store up to 20 routes with as many as 250 waypoints in each one.

Odds and Ends

To begin a man overboard maneuver using navigation data from the 540s requires that you first press the Mark button, then select the MOB function and confirm.

Once done the unit creates a waypoint, switches to the chart page if you’re not already on it, and opens data boxes giving navigation information back to the MOB position.

Screen redraws on the Garmin 540s are fast under most circumstances and only slowed significantly when a Visions card is installed on the unit’s card slot.

We tried both North Up and Course Up chart orientation on the Garmin and both worked very well. It responded quickly when turning in the Course Up mode.

Selecting the Where To from the Home page lets the user view locations for service, fuel, and repairs, as well as waypoint and route lists. Tides, current, and celestial data is found from the Information page. You can also access this type of date from the chart page by putting the cursor over the facility or area in question.


The Garmin 540s internal sounder is capable of putting out a maximum of 500 watts of power when coupled to the 50/200 kHz saltwater transducer. We used a transom mount version of this transducer for our testing.

garmin 540s sounder screen

Our test targets produced prominent fish arches when using the 50 kHz display mode.

When using the 540s with an 80/200 kHz freshwater transducer the unit will put out a maximum of 400 watts.

The fishfinder has all the features you’d want in a unit this size and includes a dual frequency view, A-scope, zoom, and bottom lock.

During our testing the 540s sounder marked all three of the submerged targets we placed in the water clearly even with auto gain set.

We made some fine tuning adjustments by switching to manual and reducing the gain settings. This cleaned and improved the view of our test targets significantly.

Gain, depth, frequency, zoom, and A-scope can all be adjusted easily via a menu that appears onscreen once you press the menu button with the fishfinder page is displayed.

This fishfinder has plenty of powerful features and worked well in all auto modes and even better after doing some manual adjustments. Our testers found it easy to operate and use.

Shop for the latest Garmin 540-series chartplotter combos here.

Final Thoughts

If you can forgo the higher screen resolution and find the 500-watt sounder adequate the 540s is a real steal as it features same highly intuitive software package as its more expensive cousins at significantly less cost. The 540s has a 1-year warranty and an IPX7 waterproof rating.