Furuno 500 manual Spiral, Example of spiral maneuver in turn mode

3. STEERING MODES

SPIRAL

The boat will spiral in the direction of current heading (STBY), set course (AUTO) or the course to the next waypoint (NAV) that was active at the moment that the SPIRAL mode is selected. The radius of the “spiral” can be set in the menu. This is same as RADIUS OF ORBIT.

In the NAV mode, the boat steers toward the waypoint (s) spirally. Note that the NMEA0183 sentence AAM is required from the plotter, and the arrival alarm range must also be set on the plotter.

Note 1: In the NAV mode, the SPIRAL deactivates the manual waypoint switching. (See paragraph 3.3.3.)

Note 2: If the boat does not enter the arrival alarm area, it may not be switched to the next waypoint. Set the arrival alarm range as large as possible and activate the perpendicular function on the plotter connected.

The boat will continue to orbit until the [AUTO] or [STBY] key is pressed.

SPIRAL starting position

d (radius of orbit)

Orbit of the center of spiral

L

(Distance between centers of spirals, see next page.)

Example of spiral maneuver in turn mode

To execute the spiral, do the following.

1.Press the [MENU] key to show the main menu.

2.For AUTO or NAV mode, rotate the course control knob to select the “SPIRAL SPEED.”

For STBY mode, select “PARAMETER SETUP” in the main menu, and then press the course control knob to show the PARAMETER SETUP menu. Select “SPIRAL SPEED” in there.

3.Press the course control knob.

The current value is circumscribed with a double rectangle.

4.Rotate the course control knob to set the spiral speed (Setting range: 0.1 to 8.0 kt.), and then press the [MENU] key twice in that order.

Refer to the formula in below to set the radius of orbit and spiral speed.

L (distance between centers of spiral: nm) =

Vs (ship’s speed : kt)

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