Navigation and Seamanship

6.4.5. Use of GPS in marine navigation and fishing

 

 Fishing vessels require electronic equipments for safe navigation especially to know their position at sea and to go through planned routes and also to locate Potential Fishing Zone (PFZ).The details of places where the fishes are expected to aggregate more (PFZ) could be obtained from remote sensing agencies. . In India , Remote sensing agency stationed at Hyderabad gives information about PFZ (Potential Fishing Zone) for the benefit of fishermen. Fishermen require GPS to indentify the PFZ. GPS is a recently developed equipment which is easy to operate, very convenient, very accurate and reliable. The unit is very simple, no license is required to operate. Accuracy of the instrument is ± 30m. The system available as a small unit can be installed even in small fishing vessels conveniently to indicate the latitude and longitude.The fishermen operating country crafts such as catamarans can have the handheld model of GPS..

Modern GPS are now available with a several new facilities – the operating can decide the destination point of points and the instrument will give directions for shortest route to those points as well as returning back. This ensures safe voyage without wandering in the sea. The instrument gives alarm when the vessel deviates away from the desired route. It also gives from the desired route. It also gives the speed of the vessel and also total distance traveled at different times.

In addition to the position and velocity of fishing vessels, a modern GPS will be giving the following information

• A course to steer to the waypoint (continually updated).
• The distance to the waypoint (continually updated).
• Once underway your speed (continually updated).
• The time it will take to get to the waypoint at your current speed (continually updated).
• Turn, Steer or Off-Course Error -- the GPS should tell you when you are off course and what direction to turn to get back on course.
• Various alarms should be available such as:
  • An arrival alarm which sounds when approaching a waypoint.
  • A proximity alarm which sounds when you come within a preset distance of any of several waypoints, regardless of whether they are your destination.
  • An anchor alarm which sounds when you travel more than a preset distance from a waypoint.
  • An off-course alarm which sounds whenever you are exceeding a preset distance from your intended course.

The readings of GPS could be used in combination with an autopilot, radar, or plotter for further advanced automatic and safe navigation.