Garmin 521 User Manual

Using Charts 

Hazard Colors—Turns hazard colors on or off. The Off setting 

shows the land as seen from the water. The On setting indicates 

shallow water and land with a color scale. Blue indicates deep water, 

yellow is shallow water, and red is very shallow water.

Range Rings—toggles the range rings on or off to provide distance 

measurement.
Safe depth—adjusts the depth at which red indicates dangerous 

depths.

Lane width—adjusts the width of the course line drawn when 

navigating. This setting also affects routes (Route To), but does not 

affect automatic guidance (guide To).

Using the depth contour lines of the BlueChart g2 Vision 

cartography, Fish Eye 3D provides an underwater view of the sea 

floor or lake bottom. Use the Range keys to adjust the view.

  NOTE: You must have an “s” series unit (such as a GPSMAP 420s) 

and a transducer wired through a marine network to receive sonar 

information.

To access additional settings or options for the Fish Eye 3D screen, 

press 

View—selects a fish eye view of fore, aft, port, or starboard.
Sonar Cone (only available if sonar is present)—turns a cone that 

shows the area covered by your transducer on or off.
fish Symbols (only available if sonar is present)—displays 

suspended targets (such as fish). Targets are indicated by red, green, 

and yellow spheres. Red indicates the largest targets and green 

indicates the smallest targets.