Garmin GPSMAP 78sc Waterproof Marine GPS and Chartplotter

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 polarized. I stumbled onto that by accident today on a hike while wearing my polarized sunglasses. I noticed that when turning the device at a right angle the image suddenly disappeared. That only happens when you are viewing a polarized lense from another polarized 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.UPDATEI 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've owned the 76s and the 60csx. The first thing I noticed with the 78 is the lack of a decent manual, even online. Thankfully, most of it can be figured out. The triaxial compass makes a real nice difference compared to the 76. The case seals on this unit definitely don't seem as durable as the 76 and I think that's likely the issue many people are having with leaking. I don't like that there are exposed screw heads too....salt water is going to have a field day...they aren't even galvanized. The screen is the same as the other two...it's decent and I do expect the same good battery performance. The sat pickup is very quick which is nice. So far so good but I do suspect that there will be problems with the battery seal door, the USB seal and the antenna seal so I'll be sure not to test it floatability. I've had the 76 fall in the water twice with zero issues. So, no manual to speak of and the PDF stinks...and no soft sided case included like with the 76. Thus...the one star demerit.Update: After having used this through Quetico and having used the old 76 there as well, it's night and day tracking with the 78s. The triaxial makes the thing absolutely stellar. Updating to a 5 star since for me, the actual features outweigh the lack of case / decent manual. You will not be disappointed if route tracking with this thing.

I chose this "marine" GPS for use on my motorcycle over the 62 because it has the robust 4-pin power connector. The buttons on top aren't terrible - but not ideal either.The unit is quite accurate, even in deep canyons and with thick canopy overhead, I've never had it not know where I am. The screen is clear and quite readable even in bright light. It takes the beating of handlebar mounted desert riding very well. I've crashed on it pretty hard and had it fly out of the RAM mount to find it 15 feet away.I like the power options - being able to grab it off the bike and take it hiking is great - also nice peace of mind that I'll have a GPS if I have to leave the bike due to malfunction. The battery life on 2200mah rechargeables is about 1.5 - 2 days of use.There are a few downsides which made me give it 4 stars.There's no way to make the backlight stay on, can only keep it on for 2 minutes at a time. Annoying since I also use it as my speedometer.The maps are expensive, and you DO have to buy one to get any sort of functionality from it. There are sites that make good, free, routable maps but the Garmin maps are not cheap.The way it breaks up routes and tracks is confusing and unintuitive.And finally - this applies to the base model only - but when you stop, since there is no compass your arrow spins around in a circle instead of staying the direction it was pointed last, making finding your way at intersections difficult at times. I can't possibly see a reason for this except to make you wish you'd ponied up the extra money for the unit with the compass (which I do).

Very nice, a lot of function for the money. I spent 6 weeks sailing the Bahamas (Spring and compared the chart quality of this unit to an large chartplotter mounted on my boat and an IPAD loading with the latest Garmin and Navionics charts. The charts on this little handheld were the most accurate! This unit showed individual coral heads correctly. Amazing. Depth contours were more accurate than the others and when we had to navigate through shoal passages, I relied on this Garmin handhold, it was spot on.I used it in my dinghy and it got wet occasionally. One time I noted the back cover wasn't sealed properly, check it carefully. I ended up with a little fogging in the LCD once in a while but it worked great. I wonder now about long term, as anything in salt water......