We tested five chartplotters, all costing less than $1,500, for ease of use. Here they are, in alphabetical order:

GARMINGarmin's GPSMAP640 was the lone touch-screen.

Garmin GPSMAP 640 – This unit lists for $1,199 and includes both marine and on-the-road navigational data. It's waterproof to IPX7 standards, has a 5.2-inch WVGA, and is NMEA 0183 compliant. This was the only unit in the running with touch-screen controls.

INTERPHASEInterphase's Chartmaster iPro.

Interphase ChartMaster iPro – The iPro lists for $999 and has a built-in sounder, as well as the chartplotter. It's expandable with Interphase radar and/or AIS, and features a 7-inch LCD screen with a wide-ratio (16:9) format. Satellite imagery is built-in along with a world base map, which is expandable with C-Map chartography.

NAVICOThe HDS7 is one of the newest units in the bunch.

Lowrance HDS 7 – This unit (which starts at $950 but goes up as you add built-in mapping options and accessories) features chartplotting/fishfinding capabilities on a 480 x 640 pixel, 6.4-inch super VGA screen. Insight mapping can be built-in and is expandable with Navionics chartography, it's NMEA 2000/0183 compatible, and can be Ethernet networked.

RAYMARINEThe Raymarine AD50, one of Raymarines smallest units.

Raymarine A50D – The A50D chartplotter/fishfinder starts at $999. Its 640 x 480 pixel 5-inch color display is hi-res VGA, and the unit is waterproof to IPX6 standards. Chartography can be upgraded with Navionics cards, it's NMEA 0183/SeaTalk compatible, and can overlay AIS information.

STANDARD HORIZONThe Standard Horizon CPF300i was the least-expensive unit competing.

Standard Horizon CPF300i – This unit retails at $849, and has an on-board fishfinder that needs only a transducer to go active. It's 480 x 800 hi-res LCD screen is 7-inch and features a wide-screen 16:9 aspect ratio. The unit has a built-in base map, which is C-Map expandable. The CPF300i is also AIS/radar/video expandable.