Knowledge Base
How much antenna separation do I need on my boat?
Many marine vessels have multiple antennas for VHF, radar, GPS, and other systems. It’s important to keep these antennas isolated from each other to prevent noise that can cause interference between these systems.
Vertical separation between antennas always provides better isolation than horizontal separation. If vertical separation is not possible, here are the suggested horizontal distances between various types of marine antennas, as recommended on page 31 of the issue
of Sea Magazine:
Minimum antenna spacing (in feet)
VHF
GPS
SSB
Radar
Cellular
SATCOM, etc.
VHF
3
3
3
2
2
3
GPS
3
0.5
4
*
5†
3**
Single Sideband (SSB)
3
4
10
4
2
4
Radar
2
*
2
2
1
4‡
Cellular
2
5†
2
1
1
4
SATCOM, TV, Data, Weather,
Voice/FAX, Video
Voice/FAX, Video
3
3**
4
4‡
4
6
* Outside of radar beam, either below or above.
** Below SATCOM beam.
† Cellular transmissions can interfere with GPS reception.
‡ Outside radar array by 6 feet.
