Radar position overview

The optimum height for a Radar scanner is high enough above the waterline to give a long range line-of-sight to the horizon, but not so high as to be adversely affected by the vessel's pitching and rolling.

The scanner must also be mounted where it is:

Above head height.
Easily accessible.
As near as possible to the vessel's centerline.
On a rigid and stable platform, capable of securely supporting the scanner under seagoing conditions.
For GPS, ensure unobstructed view of the sky. Avoid large structures above the antenna.
Clear of large objects such as the flybridge, large engine stacks, searchlights, horns, masts etc.
Clear of heat and fumes.
At least 1 m (3 ft) from a magnetic compass or other scanners.