Recommended Spacing for Rooftop Marine Equipment

When it comes to outfitting your vessel with modern marine electronics, the top of your T-top, radar arch, or pilothouse roof becomes prime real estate. With radar domes, satellite antennas, GPS sensors, lights, and cameras all competing for space, proper placement is critical. Misplacing one component can cause interference, degrade performance, or even create safety issues.

Here’s a practical guide to recommended spacing for rooftop marine equipment to ensure optimal function, safety, and longevity of your systems.

Why Spacing Matters

Electromagnetic interference (EMI), signal shadowing, and physical obstructions can occur when devices are placed too closely together. Proper spacing helps:

• Prevent radar shadowing from antennas or lights
• Ensure satellite domes have a clear sky view
• Avoid EMI between radar and GPS units
• Reduce noise or distortion in sensitive equipment

1. Radar Domes and Arrays

• Clear View: Mount as high as possible for the broadest line of sight.
• Distance from People: Ensure radar is at least 6–8 feet away from crew/passenger areas to minimize RF exposure.
• Away from GPS/Sat Antennas: Maintain 3–4 feet minimum clearance to avoid interference.
• No Obstructions: Avoid mounting in line with metal rails, lights, or satellite domes.

2. GPS Antennas

• High and Unobstructed: Needs a full 360° view of the sky.
• Minimum Spacing: At least 3 feet from radar and VHF antennas.
• Avoid Radar Beam Path: Mount above or to the side of radar domes.

3. Satellite TV and Communication Domes

• Stable Platform: Mount level and away from radar to avoid signal interruption.
• Spacing: 3–5 feet from other antennas or lights; avoid being behind radar beams.

4. VHF and AIS Antennas

• Vertical Separation: Ideally at least 3 feet vertically from GPS antennas.
• Horizontal Spacing: Minimum 6 feet from other VHF antennas to avoid cross-talk.
• Mount as high as possible for maximum range.

Every boat is unique, so while these guidelines offer a good starting point, it’s essential to factor in your vessel's layout, boating style, and equipment types. If you're ever unsure, consult with a certified marine electronics installer.

At Marine Electronic Pros, we help boaters make informed decisions for smarter installations. Whether you’re outfitting a sportfish, cruiser, or center console, we’re here to help you navigate the tech — the right way.