I use my 276C exclusively for boating, and it performs admirably. Once you figure out how to navigate the menu screens, you can take advantage of some very powerful options which you would only expect to see on higher end GPS models. Overall, I am very pleased - setup was a breeze, never a problem with position refresh, battery life is good, data is accurate, signal strength is fantastic in my boating area, and I really like the fact that nearly every screen is customizable.

However, in order to take advantage of the 276C's many IMPORTANT features you should plan on spending (quite) a few more $$$. For starters, the marine base map is garbage for those who boat offshore or cruise the coast. I wasn't expecting much in the marine base map department going into the purchase, but for those that are expecting this, plan to pony up an additional $150 for a (proprietary) data card which gives you the detail you'll need to navigate the waters safely. Also, the absence of a 12v adaptor is a real miss. Given the unit is marketed as "portable", why Garmin opted to not include one is a mystery to me. So, plan on spending another $25 for that. If you plan on using this GPS for boating I would recommend the display cover... another $20.

One of the more powerful feature I plan to utilize in the near future is the sonar function. To enable this feature, you'll need Garmins analog scanner (GSD-21) and a suitable transponder. One other feature I enjoy is the mapsource software that came with the unit. From this, you are able to upload your trips to the computer. From there you can analyze your trip - it even interfaces with google maps to provide a real-life view of your excursion. Pretty cool stuff.

I've been using my 276C since they came out.

I race and cruise sailboats from my home port in Southern California but have used also it many times in Mexico, the East Coast, the UK and The Netherlands. It is a remarkably functional and reliable unit. I've also used it occasionally for land based travel and though this is not my primary interest, I have been quite satisfied.

I have a chip so I can navigate the ports of Baja and Southern Mexico and it works seamlessly and A-OK. I still have paper charts on board but rarely use them other than to see the big picture. (To be fair, I should add that I also have a bigger, fancier RayMarine chartplotter/radar display unit at the helm, but I prefer my 276C for all uses except autohelm.)

Without question it is the best product out there for how I use it.

Oh, about 3 years ago I lost the unit overboard in Catalina in about 20' of water. I could see it down there but it took me several dives to collect it. Naturally it was non functional but I sent it in to Garmin and they sent me a new one for the $250 "repair" fee (including shipping). Took about a week.

The Garmin GPSMAP 276C is a powerful GPS, with many features. It can do topo, sonar, car navigation, bluechart marine. It works well, although it is not as user friendly as some units. Be prepared to read the manual several times to be fully comfortable using this gps. The other gripe I have is the map that come loaded on the unit is Americas AutoRoute and is pretty worthless, as it has very little detail. Also I think the Garmin folks do consumers an injustice by making the purchaser buy all the software(expensive) needed to make this unit work as intented. Also, the proprietary data card(doesn't fit anything but Garmin) is expensive. If you want speech you have to buy a seperate speaker that is built into the car charger cord. I really like this unit and to get what I wanted, ie, topo capability, car navigation and a large screen this is what I had to get. The screen is very clear and can be read in the bright sunlight. Other large sceen car navi units are limited as to what they can do. The Magellan 2500T is close and comes with topo maps, but they lack detail and are almost useless. I am pleased with my purchase but buying the unit was only the start.

Not only are these GPS unit expensive but adding a data card and additional software is really expensive. A person is able to buy a pretty slick computer for what these units and software total.

Without having seen one of these 'in person', I was surprised at how small the screen is. Also surprised that even though the device defaults to 'marine mode' (which is what we purchased it for), we had to spend another $150 on a data chip to see anything remotely 'marine'.

This should have a better description - not the fault of Amazon, though. I looked at various places to purchase and none were clear on these items.

This GPS unit is a true asset for marine use. The refresh speed of the mapping page is very fast and the button use is intuitive. Only gripe is the 12v charger lead purchased separatley broke after less than one week.

I am happy with this chartplotter but right now I wouldn't recommend it. For one thing Garmin nickels and dimes you to death if you want to actually use this. The memory is very expensive and proprietary. You need to buy additional memory to download any charts into this device. And the charts are VERY expensive and come with all kinds of obnoxious copy protection. Also worth mentioning is that the screen is hard to read in broad daylight. But the deciding factor is that Garmin is just now rolling out their next generation units that will replace this one. I would wait the few weeks it will take to get one of the new ones which will use standard SD memory and provide bigger, brighter screens, etc.

I'm a Amazon River Pilot and I use GPS only for marine navigation. The GPSMAP 276C is a good equipment but in my opinion has too many features that most people do not use. Before I had a 176C that was much more easy and quick to use for marine navigation: it was made for that. The only advantage I see in the 276 is it's better screen resolution. I only got the 276C because my 176C had a problem in the screen and I could not get a new one as it had been descontinued. Also Garmin charts are very bad for the Brazilian coast: I do not understand why they use charts from so many countries that do not have good information about the Brazilian coast ( russian charts for exemple ).

A multi-functional GPS wonder, But... be sure and have a hefty stack of money if you want all the maps, bells and whistles that make this unit so remarkable. Lets start with the main reason I purchased the 276c, for my boat. The Blue Chart marine maps combined with the flexability of the unit makes even complex marine navigation a snap. The large screen allows me to see my position on the water at a glance. Even in areas that are wrought with hazards and multiple channel markers the screen shows everything I need to know to safely navigate at any sunlight angle. When I moved it to my car, I enjoyed the same features that made it great on the water. The turn by turn routing (with voice) and the big screen worked flawlessly. Using it for land nav was also enjoyable except for the size of the unit making it a bit cumbersome. Regarding other peoples complaints about Garmins tight hold on its pricey mapping products, Well they are in business to make money, they have great map products, and you usually get what you pay for. Overall I am very pleased with this product, with the only real downside being the high cost of obtaining all the additional "proprietary" goodies you need to flesh the system out for multiple usage. Again you get what you pay for and for the price I would say that this is one of the finer GPS units on the market.

If you purchase a Garmin product, especially this one, you are firmly in the clutches of a Company that gives you what they want you to have, not what you might want. Everything Garmin makes is proprietary so that nothing else will work on a Garmin. You will be unable to transfer data to Garmin media, you will be insulted by a website either written by or for aliens and should you call the customer service or cartography lines assuming you wish to wait and wait, you will get to talk to people so uninformed about Garmin products your wait was wasted. The dingus works ok with Garmin chips, but the chips are inadequate or incomplete.

If you should have a Mac, Garmin leaves you totally unsupported so that if you choose a Garmin you need to buy a PC, a downloader, and Garmin chips to go with Garmin's vastly overpriced CDs. In short, if you prefer unsupported products that are designed to force you to buy from a company indifferent to their customers, Garmin should be at the top of your list with their GPSMAP 276c.