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Garmin GPSMAP 420/420s

alaTest has collected and analyzed 16 reviews of Garmin GPSMAP 420/420s. The average rating for this product is 4.4/5, compared to an average rating of 4.0/5 for other GPS for all reviews. Views about the memory and design are on the whole positive. The durability and price are also mentioned favorably. There are some less positive reviews about the screen. Comments are divided on the performance.

usability, price, durability, design, memory


We analyzed user and expert ratings, product age and more factors. Compared to other GPS the Garmin GPSMAP 420/420s is awarded an overall alaScore™ of 75/100 = Good quality.

Review analysis

(Based on 16 reviews)

User Reviews  

Showing 15 review(s)

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Showing 1 - 13 of 15 Show Reviews: in English | in other languages (1)

Consumer review ( review summary for Garmin GPSMAP 420/420s


alaTest has collected and analyzed 3 user reviews of Garmin GPSMAP 420/420s from The average user rating for this product is 5.0/5, compared to an average user rating of 4.0/5 for other GPS on

100% of the reviews on give this product a positive rating.

This summary is based on the products: Garmin GPSMAP 420S 4-Inch Waterproof Marine GPS and ChartplotterGarmin GPSMAP 420S 4-Inch Waterproof Marine GPS and Chartplotter

Sep, 2018

Consumer review (

Completely let down by this unit


Fashion method and use the Garmin for a backseat driver. Generally it works Well. I find the Volume on the unit when I get a call on my Blackberry Pearl is too low. Also I was in Weston, Florida and when I was approaching my Hotel the unit would keep...

Route planner needs a lot of work


Mar, 2009

Consumer review (

Garmin 420s - good for fishing


This one came with large 4" QVGA display and 320x240 pixel makes your eyes more confortable. Built-in satellite-enhanced worldwide basemap and simplified user operation. It already contains worldwide satellite images in place of more traditional maps...

4" QVGA, dual frequency transducer, CANet


Nov, 2008

Consumer review (

Great little hard drive!


I bought a refurbished hard drive of of LaCie's website because it was a lot cheaper. The first one the sent me didn't work, but they were quick about getting me a new one that did work!

durability, software, mac friendly


Jun, 2008

Consumer review (

Very good performance


So at the office we have 4 of these. We use them to go on location and to take files to and from work. They have taken a beating and we have not had any problems.

cheap, durable, performs well

doesn't feel durable, even though it is

Jun, 2008

Consumer review (

Kodak ZD710 Digital Camera


I recently purchased this camera prior to going on our vacation. It takes excellent pictures. Very clear. I would suggest this camera to anyone that is looking for one that is easy to use. Since we have been back, we have also taken a lot of up close...

Clear pictures, Easy to use


May, 2008

Consumer review (

Kodak ZD710 Digital Camera


I love this camera. It takes clear pictures with out being to complicated. It is easy to use and very little hassle. It captures action shots with out being blurry. It doesn't use much battery. Kind of awkward to hold until you become comfortable with it.

Great shots, 10x zoom, pop up flash

Doesn't come with rechargeable batteries

May, 2008

Consumer review (

Great price, great performance


I was looking for a color printer that wouldn't require me to buy new ink cartridges every time I had to use it. this was usually the case with ink-jet printers in my long experience.

Affordable price, easy setup, nice output

Bulky, expensive toner, printed colors didn't match the screen display properly

Apr, 2008

Consumer review (

Great player for your money


My son out grew his mp3 player and i began my quest to find the next perfect mp3 player for him with an expandable memory card slot. As i bargain shopped for weeks this item caught my eye. It certainly is worth the price. My son is excited with the...

you can buy a extend memory card and extend it capacity. Easy to install

The cord is so short. Need to improve on the cord length

Mar, 2008

Consumer review (

Very versatile MP3 player!


I have been nothing but impressed, with this little MP3 player by Creative! Shopping around for MP3 players these days can seem to be a very daunting task with so many on the market. Trying to compare size, features, and price took me weeks. I finally...

Very versatile, compact, light weight. Incredible sound and video. Great battery life

No wall charger, needs to be charged before initial use. Hard to find accessories stocked

Mar, 2008

Consumer review (

Pretty player, Great Sound/Battery Life


Are you looking for an mp3 player but may be tired of hearing about the "ipod"? Look no further--this is the player for you. Creative has always been known for great sound, and they have even had a line of reliable mp3 players, but this new Zen takes...

Great battery life, sound quality, screen size

Buttons feel cheaply made

Mar, 2008

Product Specifications

The GPSMAP 420s is a sleek, space-saving chartplotter that features an ultra-bright 4" QVGA display, built-in satellite-enhanced worldwide basemap, and simplified user operation. The 420s also has an SD card slot so you can add additional features with the optional BlueChart g2 Vision card. The 420s's basemap contains worldwide satellite images in place of more traditional maps, and its SD card slot makes it easy to add additional maps without connecting to a computer. With fewer keys and a simple, intuitive interface, the 420s makes navigating your way through the water easy. The GPSMAP 420s comes with a powerful dual frequency transducer that clearly paints depth contours, fish targets and structure whether you're fishing in fresh water or off the coast. The 420s is also CANet compatible, so you can share sounder data with another chartplotter on your boat.

Built-in Display

Diagonal Size:4"
Diagonal Size (metric):10.2 cm
Resolution:240 x 320


Color of product:Grey
Form Factor:Handheld

Dimensions & Weight



Display Resolution:240 x 320
Display size (HxV):2.4 x 3.2
Display size (HxV) (imperial):2.4 x 3.2

GPS Performance

Acquisition times - autolocate:120
Acquisition times - cold:45
Acquisition times - warm:15
DGPS accuracy - position:118.1
DGPS accuracy - velocity:0.05
GPS accuracy - position:590.6
Update rate:1
WAAS capability: Yes

GPS System

GPS Functions / Services:MOB (Man Overboard)
Receiver:12 channel
Recommended Use:Marine
Type:GPS receiver

GPS Type

Auto: No
Aviation: No
Geocaching (GPS stash hunt): No
Marine (chartplotters, sounders): Yes
Outdoor (hiking, trekking): No
Sport (fitness, running): No


Packaged Quantity:1
Product Line:Garmin GPSMAP


Audible alarm(s):Y
Audible Alarms: Yes


Map view options:2D, 3D


Waterproof: Yes


Routes quantity:20
Tracklog Points:10000
Tracks quantity:20


Bluetooth: No

Operational Conditions

Operating temperature (T-T):-15 - 55
Operating temperature range (T-T):-15 - 55

Other Features

Power Requirements:10 - 35v DC

Technical Details

Color of product:Grey
Form Factor:Handheld
Interface Type:Thumb Stick
Number of Waypoints:1500

Weight & Dimensions