NorthStar Navigation EXPLORER 657 operation manual Appendix C Glossary and navigation data

Appendix C - Glossary and navigation data

Glossary

Attention Area - An important area on a chart, such as a restricted anchorage or a shallow area (see section 17-2).

AIS - Automatic Identification System. A System where vessel information (location, course, speed, etc.) is broadcast by VHF radio, for use by other vessels in navigation and collision avoidance.

Bathymetric line - A depth contour line on the chart.

Chart card - A plug-in card that stores chart data for a region (see section 1-3).

C-MAP™ chart card - See Chart card.

C-MAP™ user card - See User card.

CPA - Closest Point of Approach. The closest distance two vessels will come to each other based on their current course and speed.

Cursor - A symbol on the display (see section 3-2).

DGPS - Differential Global Positioning System. A navigation tool based on GPS with some errors corrected (see section 7).

DSC - Digital Selective Calling. A feature of marine radios enabling communication between specific vessels, as well as distress alerts.

Goto - A simple way of navigating straight to a waypoint or to the cursor position (see section 3-1).

GPS - Global Positioning System. A satellite- based navigation tool (see section 7).

Leg - The straight segments of a route between waypoints. A route with four waypoints has three legs.

MMSI - Maritime Mobile Service Identity. Unique identification number for a vessel, for use in Digital Selective Calling.

MOB - Man overboard.

MOB function - Starts navigating back to the place where someone fell overboard (see section 2-4).

NavBus - A way of connecting Northstar instruments together to share data (see section 18-9).

NMEA - National Marine Electronics Association.

NMEA 0183 - A standard for interfacing marine electronic devices (see section 18-10).

Route: Two or more waypoints linked in sequence to form a course for the boat (see section 6).

SmartCraft - A feature of Mercury Marine engines for monitoring engine performance.

TCPA - Time to Closest Point of Approach. Time until the closest point of approach for two vessels.

User card - A plug-in card that stores waypoints, routes and tracks (see section 1-2).

UTC - Universal Time Coordinated or Coordinated Universal Time, which is a standard world time, formerly called Greenwich Mean Time (GMT).

VHF - Very High Frequency. The frequency range used by marine radios.

Waypoint - A position that you can set on the 657 chart, for example a fishing spot or a point on a route (see section 5).

90 Northstar Explorer 657 Installation and Operation Manual