Garmin GPSMAP 78s with Built-In Worldwide Basemap

I got my Garmin 78sc a couple of weeks ago, to use not only on the water (Chesapeake Bay), but for hiking and geocaching. By now I've sailed for 3 days,(about 15 hours total run-time), and the alkaline batteries are about half gone according to the meter, so I'm fairly satisfied with the battery life. I haven't tried NiMH rechargeables yet.

I was concerned the unit was going to be huge (it's intentionally large to give internal air space for water flotation ability), but it's not too big or heavy. It was smaller than I was expecting it to be. Also, having the buttons on top of the screen are a little weird, but it's not a big issue in use. It's very fast in finding the satellites and switching display screens, etc. The built in electronic compass (multi-axis)calibrates quickly, and reacts quickly to movement, but seems very accurate. There is an option to have the map orient to either the compass heading (direction you point the GPS) or from the track (direction you were moving in is oriented "up").

This is my third hand held GPS--before this I had a high end Magellan and a DeLorme with topo maps. I am much more impressed with this unit than the others. Of course, technology marches on, but the famed "ease of use" that Garmin GPS's are known for, along with the raw capabilities of this unit for marine use are there along with the faster speed. So far, I'm very happy.

It has all the marine functions I was hoping for. The included g2 coastal marine charts are good, very readable in bright sunlight. It has a "Man Overboard Button" where when pressed and held, not only marks the position, but immediately give you the option to navigate back to that position. It also has "Anchor Drag" alarms, as well as low water depth and high water depth alarms (that key off the chart depth readings from low tide). All these alarms are adjustable by the user. I bought a separate Garmin boat mount made for this unit. I have not mounted it on the boat (3 screw holes required), but it seems to hold the unit well, with some adjustability for viewing angle.

Like all handheld Garmins, the "basemaps" on the 78sc (on land, not on the water)are fairly useless, and optional maps can be expensive. I recently loaded the separately purchased TOPO 100K US maps on DVD. When I loaded as many map regions up to the 78sc's internal memory (1.6GB I think?), about 70% of the continental US would fit, and it took a few hours to convert and upload via USB. I did not try loading up more maps to a separate MicroSD card. I have not used the topo maps yet, or the Geocaching functions of the Garmin unit, but they seem impressive looking at the menu options.

Like I said, so far I'm very impressed, and looking forward to learning all the other capabilities of the unit, as well as checking out the Topo maps and Geocaching functions.

I've had some experience with the older GPS 76 and found it very hard to see in bright sunlight out on the water.

So, I was a bit nervous in ordering the GPS 78sc without being able to kick the tires. It arrived yesterday and I've spent about 6 hours total getting used to it. There were several concerns that I, at first, felt like I had bought a pig in a poke -- BUT, after a couple of phone calls talking to the Garmin technical people, all my issues were resolved.

This device is simply incredible with its accuracy and features for such a small package. I rely heavily on the MOB (man overboard) screen for use in setting upwind marks at specific bearings and distances from the committee boat in Race Committee work for Offshore classes. The color screen is very easily seen in the brightest conditions. The track log and reciprocal bearing back to the committee boat are highlighted in different colors and make for a superb display.

One of the reasons the color screen is so good (and they don't mention it anywhere) is that the lense window is polaroid. I stumbled onto that by accident today on a hike while wearing my polaroid sunglasses. I noticed that when turning the device at a right angle the image suddenly disappeared. That only happens when you are viewing a polaroid lense from another polaroid lense.

Now that I am familiar with the 78sc, my ONLY complaint is that the on-line Operation Manual is woefully inadequate for anything other than a basic introduction. However, all of your technical questions (and I am sure you will have some0 will be answered by their Customer Service department. Unlike many other companies, you won't have to wait more than a minute or so before getting through to a tech specialist. Pretty impressive.

Let me give you an example of how the Operation Manual suffers. Nothing in the on-line literature advertising the 78sc explains the setup capabilities of the compass feature. It is factory set to show a compass rose instead of degrees. I have a real need for this to be in degrees, and yet after playing with the device for over an hour, I could not locate any menu item that would allow me to change the display. I was quite disappointed in my purchase at this stage -- however, my first call to their tech people got me oriented in how to use the menu drop-down sub categories to find where I could make the setup change.

My next issue was that I consistently found the compass bearing was always 10 degrees off from measurements made with my hand-bearing compass. I must have performed the compass calibration in the 78sc a dozen times -- all to know avail. Unbeknownst to me, the factory default for the compass feature is for TRUE north instead of Magnetic north. In my region of the country, eastern Virginia, the angular difference between true north and magnetic north (known as the declination) is ---- Ding ding --- 10 degrees. I stumbled on this by again calling the tech support and was led to the menu item where I could switch from True North to Magnetic North. The devices is now dead on with my hand-bearing compass.

I also will be using this for my hiking adventures and purchased the Topo 24 -- Mid-Atlantic sw to provide topographic detail. This along with the built-in altimeter make this a powerful tool to have in your backpack.

Having owned this for only two days, I obviously cannot speak to the reliability of the device over long term exposure to saltwater, etc. I had read a few negative reviews from purchasers on this issue on several other websites. But, I intend to keep such exposure to a minimum (i.e., not leave the device on-board), so I do not think this will be a problem for me.

UPDATE
I spent most of the day yesterday out in the bay doing mark boat duties for our Race Committee. The 78sc performed flawlessly and the accuracy of the MOB feature (pinging on the committee boat) was amazing. As the committee boat stayed put the whole day, I only had to ping it once and from then on I had accurate bearings and distances for setting and moving the upwind marks and the pin end of the starting line.

I set the device on the top of the dash in the center console and it never budged, even in choppy waters, thanks to the rubber backing on the GPS.

The coastal chart info is also detailed and accurate.

I honestly cannot think of anything I would do to improve this device. If you have a need for it -- don't hesitate, buy it.

I was in the market for a new GPS and came across this model while doing some research on the web. Although the Garmin GPSMAP 76 was available at very good prices, I decided to opt for the newer GPSMAP 78 model. I this will be only the third GPS I have owned in the past 15 years, so I wanted the very latest generation. The GPSMAP 78 has a very good feature set. It acquires a location very quickly after powering up. I was able to transfer waypoints to the unit when connected to my PC by using Google Earth. Very slick and easy! The only downside so far it the unit has lots of options and setup features. I'm still trying to remember them, but it's getting easier. I did contact Garmin and they confirmed that the unit does NOT charge the batteries when connected to a PC via the USB cable, nor will it operate on USB power. The unit is simply a mass storage device when connected.