The Global Positioning System (GPS) is a global navigation satellite system maintained by the United States government. This space-based system offers reliable location and time data anywhere in the world. Anyone can access information from the GPS as long as he or she has a GPS receiver. For sailors who are always out there in the ocean, marine GPS systems are a must. A marine GPS system serves as a navigation tool as well as tracking tool. A boat will never lose his way in the open sea as long as it is equipped with a GPS system. The Twister Group sells several well-known and good quality brands of GPS systems for the marine environment. Most of the units are handheld or portable enough that they can be brought anywhere. The units feature an LCD display which displays location and time information. The prices of the units vary depending on the brand, quality and design of the GPS system.