Garmin 521 User Manual

Configuring the Chartplotter

  To configure settings for boats other than your own, from the 

Home screen, select 

 > 

.

  NOTE: To configure AIS or DSC information for other boats, your 

unit must be connected to an external AIS or DSC device. 

aiS—turn AIS (Automatic Identification System) on or off. AIS 

alerts you to area traffic by providing boat IDs, position, course, 

and speed for boats that are within range and equipped with a 

transponder.
dSC—turn DSC (Digital Selective Calling) on or off.
aiS alarm—turn a safe zone around your boat on or off. This is 

used for collision avoidance, and the zone can be customized.

  From the Home screen, select 

 > 

> 

.

Range—change the measured radius of the safe-zone ring to 

a specified distance from 500 ft. to 2.0 nm (or from 150 m to 

3.0 km, or from 500 ft. to 2.0 mi).
Time to (Safe Zone)—sounds an alarm if AIS or MARPA 

determines that a target will intersect the safe zone within the 

defined time interval (from 1 to 24 minutes).