What is the optimum height for a radar antenna? It is a debate that goes on 40 years after radars started being installed on yachts.

Lets review the issues:

• The ability to “see” to the limit of the useful range.
• Minimization of return of wave generated noise close in.
• Ease of installation.
• Maintenance.

Lets deal with distance first.

In theory the higher the antenna is the further it can see before the curvature of the earth comes into play. This would naturally lead you to install the antenna on the mast. But do you really need this height? If your target is high, say a mountainous island or headland, the answer is no. How about ships? They are high as well. A coral atoll? With an antenna mounted on a stern mast or barely above deck level on a mizzen the atoll (or its palm trees) shows up at ten or more miles with a good radar. Big ships often at 12 to 16 miles.

Atmospheric ducting also helps extend range beyond line of sight.

Next, the higher the radar scanner the worse the sea clutter you will find hiding targets.

Not convinced to mount your scanner low? Consider the problems of mast mounting:

• Weight of cabling and antenna up high.
• Windage interfering with air flow to the sails.
• Difficulty in installation and service.

Stern pole or backstay mounting is always best.