You can't go wrong with the 76. As far as memory, it really depends on what type of map you will use. The garmin mapping software has preselected map sizes of an area. So for example, my hometown on the Topo software is at the bottom of a map that is about 10 mi wide by 20 mi long. I can fit the majority of the state on my GPS (64 mb). In utah where there is much more data i can fit park city and local surrounding area. If all you use it for is sailing you will be fine with any memory size. If you wanted to drive from DC to seattle with detailed maps, then you better bring a laptop because there isn't a GPS that will hold that much maps. Also, if you like to roadtrip and use it, the new 60cs (color) has auto mapping software. So you punch up an address or point to where you want to go and it provides turn by turn directions to get there. The 76 and etrex just draw a straight line. Two things you will want to do: by the best dry bag for it you can and get some rechargable batteries. Salt water will crack the soft rubber surrounding the buttons and your unit will loose it's waterproofness. Rechargable batteries will last you about 12 hours of continuous use. Bring them home and in 4 hours they are back and ready to use. Buying a unit with Blue chart capability is also quit handy as it will store marine specific maps. The software is quite pricey, but i guess if you are doing alot of longdistance sailing, it might be handy. The best thing to do is go and use them to see what you like. The joystick is easy to use as it requires only your thumb but you have to do alot of clicking through menus to find stuff. They weren't really designed for "active" use. They were intended to be held in someone's hand while they are hiking. So it might be tough to read the screen while your getting rocked around. I pretty much live my life around these things. I have them in the airplanes i fly, they get me around the mountains when i'm mapping, i sail, paddle, and drive with them. It's an amazing tool and can save you a headache or two. You may also want to check out some of the Magellans. Though i'm biased towards Garmin, Magellans have some really good units with some no brainer things that Garmin should use. Example...the Topo maps have the contour spacing originally in 10 meters. So switching to feet gives contour intervals of 32.3 feet or something close to that. Another thing, if you plan on downloading lots of different maps frequently, you'll want to take into account the time it takes to do the actualy download. The unit has to erase the map memory before each download. It won't just add or subtract one map. And a map of substantial area (50-100 mi) could take 30 minutes or more. The connection to the computer is through a serial port and is hella slow. Unless all you are going to do is walk around the woods then i wouldn't recommend the etrex. 76 is the way to go and if you have the bling bling, get the new 60cs. Hope this helps!!