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Garmin 78sc Review

The recently announced Garmin 78sc is at the pinnacle of the three model 78-series marine handheld GPS lineup. Not only does this unit float, it also features a high-sensitivity GPS receiver, and two onboard sensors, an internal electronic compass and barometric altimeter.

The “c” designation in the model number indicates this portable GPS comes preloaded with Garmin BlueChart coastal charts covering U.S. waters while the “s” stands for sensor equipped.

Buy this Garmin handheld GPS preloaded with U.S. BlueCharts here.

Buy this Garmin handheld here.

garmin 78sc portable gps

Garmin 78sc

The grey, black, and silver case measures 6.0-inches tall, 2.6-inches wide, 1.2-inches thick and with a pair of AA batteries installed tipped our scale at 7.8 ounces.

The unit will lay flat in a table top and not slide around much because of rubber covering over the battery case door and protective weather flap hiding an external antenna jack, mini USB port, and a Garmin 4-pin serial connection. Rubber side grips enhance the feel in hand.

I found the Garmin 78sc easiest to operate while holding it in one hand and button pushing with the other. However, for more manually adept users it is possible to operate the pushbuttons located on the top third of the front panel with the thumb without blocking out large portions of the screen.

In the box with this floating handheld marine GPS unit you’ll find a USB cable to connect to a personal computer, a wrist strap that attaches at the case bottom, and a pamphlet size quick start manual which lists basic operating instructions.

To learn more about your 78-series handheld GPS you’d need to go to the Garmin website and read the full owner’s manual there, or download, or print it.


Eight pushbuttons, with on-button function labels, and a single 4-way rocker switch provide operational control of all functions. Two of the buttons also have their secondary function label printed on the case face adjacent to the key.

The Garmin 78sc has five main pages, each one automatically selected with a single press of the Page button gives the user easy access to most functions. Hitting the Quit button brings up pages in reverse order.

The first page in sequence is the Map page and since the 78sc is preloaded with U.S. marine charts you’ll find highly detailed cartography here.

Next you will see the Compass page with its compass rose, waypoint bearing pointer, and data boxes.

The Trip Computer page is loaded with lots user adjustable data boxes. The last main page of interest to mariners is the main menu page.

Each press of the Page button slides a page icon graphic along an onscreen tape displayed over the top the last selected page. When you stop pressing Page the new appears automatically about two seconds later. It is a very slick interface.

Waypoints and Routes

An easy way to save a present position waypoint in the Garmin 78sc is with a press and hold of the Mark button. This creates the waypoint and brings up a waypoint data page where you can either just hit enter to save it as is or change the associated icon, name, add a note, or change the latitude/longitude.

An icon can be selected from one of several large groups with names like markers, marine, or outdoors. Waypoint names can be up to long and are enter with by using the rocker and enter key to scroll around an onscreen number and letter display. This is a notch above scrolling though numbers and letters for data entry.

Use of the built-in route planner made constructing a route very easy. I simple stepped through a few menu pages to select a new route with point chosen from the map. From there you simply move the cursor and hit the enter key to add a point. Pressing quit saves the route automatically.

With a large internal memory this Garmin handheld will store up to 2000 waypoints and 200 routes. That is pretty impressive storage capacity for a portable GPS.

Display Screen

Because of their overall size the front panel on the 78-series units has plenty of room for a respectably sized display screen. The Garmin 78sc screen occupies the lower two-thirds of the front face and features a portrait layout with a width of 1.6-inches and height of 2.2-inches. This TFT color screen carries a 160 x 240 pixel resolution and measures 2.6-inches on the diagonal.

A single quick press of the off/on button brings up a screen backlighting menu page that includes the date, time, battery level, and GPS signal strength meter, as well as a 21-position slider. You can adjust the screen backlight here or keep doing quick presses of the on/off button and select either minimum, maximum, or mid-level brightness.

I am going to rate the display screen on the Garmin 78sc excellent. When I viewed it outside in sunny conditions I found it easy to read with or without my polarized sunglasses.

Odds and Ends

The man overboard function on this Garmin portable GPS is activated by pressing and holding the MOB key and then hitting enter to select navigation back to the MOB waypoint.

garmin 78sc portable gps

I found this compass page best for navigating back to an MOB point.

I found the Compass page provided the best default navigation back the MOB point. You’d simply follow the bearing needle in the compass rose and use the data box info to know when you arrive.

To effectively use the map page for navigation back you’d need to have previously setup the proper data box information or all you’d have here would be an onscreen course line. I prefer to see an MOB function that operates with a single button push and has an automatic screen switch to graphic and numerical navigation data back to the point.

A rubber covered battery compartment door located on the case back houses the batteries and the microSD™ card slot. The mechanism on this door is new for Garmin. It uses a spring release slider to open and remove the door. I found replacing the door to be a two-step process where the end with locking mechanism was pushed in first and then the bottom had to be pressed into place with both hands. If you neglected the last step the unit would lose its watertight integrity.

A mini USB port, serial port, and external antenna jack, all located on the case back, are all covered with a protective weather flap. There is an optional marine dash mount and power cable available that would facilitate permanent mounting on your boat.

This Garmin portable GPS will do a wireless data transfer with other capable Garmin units. Marine information about navigation markers, tides, currents, and nearby marine services can be found via the Find key.

This Garmin portable GPS is not only rated waterproof to IPX7 standards, it floats too, a great advantage for gear to be used aboard a boat. The IPX7 rating means it can be submerged to a depth of 1 meter for 30 minutes without suffering any damage.

It passed the dunk and drop test with no problems. The unit carries a 1-year warranty.

Buy this Garmin handheld here.

Buy this Garmin handheld GPS preloaded with U.S. BlueCharts here.

Final Thoughts

The Garmin 78cs has a bright display screen, up to date intuitive operating software, detailed onboard marine cartography, as well as lots of other marine related information built-in. I’d rate is as one of the most sophisticated marine handheld GPS units on the market today.