NAVCOMP

is a powerful navigational aid for the racing and cruising yachtsman. Tidal streams of UK and North European waters greatly facilitate rapid and accurate planning of passages and races. Automatic corrections for tidal offsets, pre-stored waypoints, PSION calendar and clock - all allow the navigator to respond rapidly to changing conditions. NMEA0183 interface for transfer of waypoints (with names) to/from a chart plotter or GPS .

*PASSAGE and RACE PLANNING

User data entry includes waypoints (or groundtrack), date and time of start, and predicted speed. Result is,
GROUNDTRACK, WATERTRACK, DURATION, ETA and APPARENT WIND
Up to 99 contiguous or independent legs can be pre-planned and stored.
It is easy to set up and calculate a leg, but the process is further speeded up by using pre-stored waypoints .
Planning of multi leg passages (or races) is made easy with the NEXT LEG function .

For on-line course correction a live link with GPS can be used

*ESTIMATED POSITION

EP, COURSE and DISTANCE made good, and average water speed from entries of ship's log, course steered, and time now.

*EP per HOUR

Predicted hourly position co-ordinates with Cross Track Error (XTE). Particularly useful in cross currents. Graphic plot of the watertrack.

*INSTANT TIDE

Tidal stream Rate and Direction for specified position and time. Tide vector diagram.

*WAYPOINTS

In Series 3 up to 234 lat/long pairs with names and INDEX can be stored. In Series 5 the WAYPOINT file is a standard PSION Data file with Card and List views, with no system limit. It can be sorted. Waypoints, retrieved by name, can be used in sail plans. They can be sent to GPS.

The file is shared with astroNAVCOMP (if installed).

*ROUTES For planning of multi-leg passages and races. With INDEX.

*OCEAN MODE

World-wide passage planning with user-entered set and drift, mag. variation/deviation, etc.

*SHIP'S TIME Sets the difference on UT, e.g BST.

*TACKING

Upwind sailing (also downwind) in reducing tacks within a user-defined segment, centered optionally on rhumb line or wind. Results include sailed distance to segment limit, tack point Lat/Long, Layline, Bearing to mark, ETA. The tack can be re-computed (for example, in a windshift). NEXT TACK continues the process.

*BEST TACK

Given the tacking angle, boat speed, and possible heading Best Tack, Port or Starboard, is computed according to tidal stream.

*TRUE WIND Computed from entries of Apparent Wind and boat speed/course.

*VMG - Velocity Made Good. Entries of boat speed/course compute boat speed component along line of wind and along rhumb line

*COMMS

NAVCOMP can exchange position co-ordinates with external navigational devices equipped with NMEA 0183 interface. The physical link is provided by a standard PSION RS232 Serial Link. The cable is terminated with a 9 pin D type female connector, which could mate with a male connector with loose wire tails or a suitable female-male gender changer.

INPUT to NAVCOMP
External input can be used in all functions where position co-ordinates are required. The remote device may be GPS or it may be a Chart Plotter.

A waypoint file can be loaded from a chart using a plotter, or from GPS.

OUTPUT
Output of waypoints from NAVCOMP is automatic. Waypoints in data entry or results tables, as well as computed waypoints, are sent out as they appear on the screen. Each waypoint is sent with the default name "NAVCOMP" for identification in the remote device.

Waypoints can also be sent from NAVCOMP waypoint files. Each waypoint is sent with its name.

*ON-LINE

This optional enhancement consists of two functions. UPDATE is used underway, at intervals in real time, to compute corrected course to steer, distance to sail and ETA, given the position from GPS, time from the PSION clock, and speed through water. Companion LOGBOOK function converts accumulated entries into a text file formatted like a ship's log book _________________________________________________________________________________________

The system must be updated annually.