boater : if you be look for a handheld GPS for marine purpose , you need to be aware that this model come out of the box with a base-loaded database that include almost nothing in the way of aid to navigation . while the older map76 model include a database of coastal navigational aid -lrb- buoy , light , nun , can , whistle , gong , lighthouse , etc -rrb- , this model do not include any of these . if you turn on this model and scroll over to Boston Harbor or San Francisco Bay , it will show you where the water be and where the land begin , but nothing more . no navigational aid whatsoever . yes , it will give you lat\/lon fix like any gp . and it will give you speed and head information . but that be it . of course , Garmin tell you that you can purchase the detailed marine chart -lrb- they cost $ 100 - $ 200 each for just a single area ... in the Northeast , you would need to purchase many of these to get complete coverage -rrb- and this be understand . but most serious boater use detailed paper chart and\/or a plotter and do not need they handheld for that kind of detail . what a handheld be good for , however , be to show where you be in relation to a bell or a light you may be run toward in the fog or in the dark or in relation to a known waypoint . the old version -lrb- map 76 -rrb- give you these bell and light . this one do not . so unless you want to add many hundred of dollar to you $ 275 - $ 300 purchase price , this be the wrong model for a handheld gp as backup . get the older map 76 instead . for less than $ 200 , you will have more than you need as a helpful boater 's unit and no need to buy electronic chart . of course , the map 76 be B&W; and not color , possibly less sensitive , and lack all the bell and whistle . but it be WAY more simple to use . this map 76csx be very complicated because it have build in all the highway , hike , climb , geocach , urban feature and capability that you will never use . just figure out the setup take hour . bottom line ... Garmin be a great product . but if you be a serious boater -lrb- not want to drop a thousand on a complicated handheld -rrb- and someopne who navigate with paper chart or a regular chart plotter , you do not want this model ... you want the map76 . many sailor just want the peace of mind from a backup . this be not it . happy sailing