• The Global Positioning System is a navigation system that provides reliable location and time information anywhere on the Earth.handheld gps image by Christopher Dodge from Fotolia.com
  
  Choosing the right marine GPS system can be a hassle. You have hundreds to look at from a variety of manufacturers, each with different features including electronic chart display systems, radar, autopilot and fish finders. Before embarking on the process of finding that perfect and elusive unit, determine what ideal features are you need and which ones you don't. Ten units in particular rise to the top of the industry.
  
  

Garmin GPSMAP 76CSx

• The Garmin GPSMAP 76CX is a 12-channel marine GPS unit capable of storing up to 50 routes and is WAAS-ready. It has a smaller 2.6-inch wide screen, built-in internal memory, internal antenna, and stores about 1,000 waypoints. It's an ideal marine GPS unit for beginners, which performs basic tasks at an optimal cost for the simple marine navigator. The average price among most retailers for this unit is $300 as of 2010.
  
  

Garmin Fishfinder 400C

• While weighing less than 500 grams, the Garmin Fishfinder 400C Waterproof Satellite Navigator has a 4-inch wide screen and impressive see-through technology that enables you to discover fish seeking shelter within covered areas. It keeps you informed of the sea floor's condition, such as sandy, rocky or soft. The Garmin's UltraScroll function works independent of speed and assess depths of underwater creatures and objects. It also incorporates AutoGain technology to maximize fishing locations and minimize underwater clutter. The average price among most retailers is $300.
  
  

Lowrance XOG

• Lowrance marine GPS units are ideal for a low-end price. Released around 2008, this unit has a 3.5-inch display, photo-viewing and audio player options, expansion slots, depth display, GPS maps, voice navigation, trip calculator, touch screen capability, marine cartography, city navigation maps of the United States, Canada and Europe. This unit is not only a capable navigator, but a portable entertainment device. The average price among most retailers for this unit is $300.
  
  

Lowrance LMS-525c

• The LMS-525C5-inch display GPS receiver has a modest price tag for the beginner fisherman and boater. It features WASS enhanced accuracy, 1,000 waypoints, expansion slots, fish finding and chart plotting technology, depth display and sonar. The LCD display has a split screen option, and the receiver is 12-channels. Included software maps cover the United States and Hawaii. The average price among most retailers for this unit is $300 as of 2010.
  
  

Lowrance LMS-520C W

• The Lowrance 520C GPS unit has a fixed form factor and various expansion slots. Software maps include the United States and Hawaii; meanwhile, marine features encompass fish finding technology, chart plotting and sonar. The high-resolution screen has a split screen option, and the unit is capable of storing 1,000 waypoints. The average price among most retailers for this unit is $550.
  
  

Humminbird 595c

• The Humminbird 595c marine GPS unit is WAAS enabled and has a 5-inch display, with 750-waypoint capability. Primary features include fish finding and chart plotting technology, marine cartography, alarms, and a 12-channel receiver. This unit also comes with a MultiMediaCard slot for expansion and a manufacturer-supplied one-year warranty. The average price among most retailers for this unit is $600.
  
  

Garmin GPSMAP 545

• The Garmin 545-series marine GPS unit is suitable for only the advanced level users. It has a comprehensive BlueChart G2 marine cartography of Hawaii, Bahamas, Alaska and the entire United States. It provides details on depth contours, tide information, port plans, and it also offers UltraScroll (present in several other top marine GPS units). The unit has an in-built analog sounder, split-screen viewing options, real time weather reports, and chart information in 3D perspective on a high-resolution sunlight readable display. The average price among most retailers for this unit is $700 as of 2010.
  
  

Garmin GPSMAP 376C

• The Garmin GPSMAP 376C is a relatively expensive marine GPS, but it comes fully loaded with WAAS enhanced accuracy, environmental protection and waterproof standards, chart plotting, horizontal accuracy, current speed calculations and a keypad. The unit also accepts map cartridges, so map capabilities are unlimited for this device. With 3,000 waypoints, a parallel-channel receiver and color LCD high-resolution display, this marine GPS is ideal for the avid boater and fisherman. The average price among most retailers is $950.
  
  

Garmin GPSMAP 540s

• For a hefty price, an experience marine user can have access to many audible features, a built-in antenna, fixed form factor, WAAS and EGNOS for enhanced accuracy, and a water temperature sensor. The high impact alloy case is waterproof and has an SD card expansion slot. The LCD display shows vivid GPS maps, marine cartography, and 15,000 waypoints. The unit features a 12-channel receiver. The device also has trip calculations such as current speed, elevation, time, and track log with an update rate of one time per second. The average price among most retailers is $1,000.
  
  

Raymarine C80

• The Raymarine is one of the most expensive marine GPS devices on the market. It has an 8.4-inch display, audible feature, high-resolution LCD display, and marine GPS maps of the entire world. Other marine features include fish finding and chart plotting technology, sonar and 5,000 waypoints. Weighing about 4 lbs., this unit is a robust fixed-form device for the advanced user. The average price among most retailers is $1,500 as of December 2010.