Here Is What WE Say About It:

I have been using GPS for over 10 years in one form or another. More than 25 models over time from laptop applications to hand held devices to automotive units to chartplotters. My current collection of GPS units totals 12. So what in the world do you need 12 GPS units for. You don’t. What I am seeking is the “perfect” unit that can do everything I expect and need a GPS to do. Is there such a beast ? Not that I have found but there are a few that are close.

For off-roading/overland travel the typical automotive GPS sold today by most retailers just won’t cut it. Sure they are great for finding the way to that new restaurant you’ve heard of, to that big garage sale on Saturday and your way around towns, cities and everywhere with a paved road in between. Unfortunately, they aren’t designed with the off-roader in mind. The smaller hand held units were designed for the wilderness and are great for hikers because of their size but for vehicle navigation the screens are just too small.

Don't get me wrong there are some very nice off-road GPS designed for in vehicle navigation. One that comes to mind is the Lowrance Baja units. The big disadvantage is that there are no Topo maps for that unit (I had a long talk with both a salesman and an engineer at Lowrance and they both lamented how their company does not support their units with software) that compare in any way to those that Garmin (or even Delorme or Nat Geo has to offer) but none of the really good software programs will operate on each others units. It's a way for the GPS manufacturers to force you to buy both their hardware and software. It's a good business model for them but not for the consumer.

That takes us to Garmin Marine Chartplotters. Not all of these units are suitable for vehicle navigation . The ones that are, while not perfect, stand out in a "sea" of GPS units. One of these units is the Garmin GPSMAP 478 and the unit that I will be using in my Jeep until something better comes along.

The 478 has many of the features that I feel are important for off-road use:

• A larger, sunlight readable color screen (twice the size of a hand held unit)
• NMEA 0183 output for connection to a laptop via USB
• Track Log – 10,000 points, 20 saved Tracks
• 3000 saved Waypoints
• 50 saved Routes
• Portable, can run 9 hours on its lithium-ion battery
• Weather/water proof and shock resistant
• XM weather compatible
• Card slot to accept additional maps
• Sun & Moon info, Tide tables and Hunt Fish calendar
• Ability to connect to APRS enabled Ham Radios via data connection cable
• Turn by turn navigation when not off-road

With its detachable external antenna, the 478 quickly picks up satellites, even indoors. The XM weather function (you need to buy the optional antenna and subscribe to the service) will show you right on the screen current weather conditions and systems right on the screen for the US and Canada. While it doesn’t offer an MP3 player, it does work quite well with XM Satellite Radio.

You might wonder why tide tables might be important. On a recent Jeep Expedition we drove the coastline of the Sea of Cortez from near the mouth of the Colorado River south to near Puerto Penasco, Mexico. Without tide information we ran the chance of being either stranded for 12 hours or being swept away by the high tide, a tide that in places comes right up against the 50+ foot vertical cliffs.

But the Track Log feature is one of the most important. Save your tracks from each trail, share tracks with friends, use tracks from popular programs like TrekNow to navigate off-road trails. Load up to 20 tracks to your unit and follow them thru a new and unfamiliar trail or on one of your favorite trails. Using saved tracks leaves nothing to chance and saving tracks on new adventures will help you navigate those trails again in the future. Is 20 saved tracks enough, the answer quite simply is NO. The GPSMAP478 will store 50 routes, why not 50 or 100 tracks Garmin?

The GPSMAP 478 comes ready for the water, the road and the trail. It has pre-loaded Garmin street maps, pre-loaded coastal maps, vehicle mount, marine mount, vehicle power cable, data cable for direct wiring (power, sound and data) and more. You will need to buy at least one Garmin Data card to load Topo software for off-roading and if you want XM weather and/or XM Sat Radio, the GXM30 XM antenna.

How does this unit perform in the real world ? Excellent ? I have tested it off the coast of Mexico using Blue Chart maps, in the cities and highways of Arizona and California and have used it extensively off-road. Is it perfect? No but it’s not too far off. So what would it take to make this unit my perfect unit ? How about a 5” or better yet 7” touchscreen, ability to save up to 100 tracks, ability to use SD cards for additional maps (the 478 uses Garmin Data Cards, hard to find, not much capacity (512kmax) and very expensive at $100-$250), and all the features of a high end automotive GPS like my Nuvi 2595LMT.

The GPSMAP 478 retails new for $799. I have seen fully warranted refurbs available online for under $600 and used ones online in the $400’s. Unfortunately Garmin has since discontinued this model but you can still find new units online at a number of places. In addition, Ebay is a great source for new and used units and all kinds of accessories.

The picture was taken in Canyon De Chelly, AZ using Garmin 24K Topo maps. The trail uses the riverbed in many places which is why it looks as if the trail is running down the center of a river.


The Garmin GPSMAP 478, it’s worth considering for the serious off-roader wanting more than the big box store automobile units can give you until something better comes along. I'm still using it as 2014 comes to a close and I still haven't found a better option!

UPDATE: Sometime after doing this reveiw I acquired a Delorme PN-60w with SPOT Communitcator. It does everything that this Garmin unit does only more. Although the screen size of the GPSMAP 478 is a bit larger than that on the PN60w, the cost of memory for use in the PN-60w is CHEAP. You can't beat the $40 cost of a 32GB SDHC card for the Delorme PN60w. The big disadvantage for the Garmin GPSMAP 478 is the fact that additional maps can only be used by transferring them to Garmin Data cards. Garmin Data cards are not only expensive but have a maximum size of 512mb which limits you. For example a 256mb data card will set you back around $150. The largest 512mb cards will cost over $200 when you can find them.

Based on the cost of memory alone the Delorme PN-60w is the best choice. It is a full featured PREMIUM GPS unit that is technically superior in my opinion to the Garmin and as a bonus has the safety, security and features of SPOT.

p.s. Someone write Delorme and ask them to make a 5" or better yet 7" GPS for us overlanders and off-roaders. ----------------------------------------------------------------------------------------------------------------------------------------