6 dB marine VHF antennas

Choosing a marine VHF antenna: 1, 3 or 6 dB

Decibels (dB) express antenna gain: how the signal is distributed. Higher gain concentrates radiation towards the horizon; it does not increase radio output power or guarantee longer range in every situation.

1 dB: a compact option where space is limited and the boat moves considerably. A broader vertical pattern better tolerates heel and rolling. Check the model and mounting requirements; 3 dB masthead antennas are also a common choice on sailboats.

3 dB: a versatile choice for sailboats and small or medium boats. It balances coverage and tolerance of movement, particularly when mounted high and clear of obstructions.

6 dB: suited to motorboats with a more stable platform and enough space for the chosen model. It directs more signal towards the horizon while upright; pronounced heel or rolling can reduce this advantage.

Choose according to boat movement and mounting position as well as length. Height above the water, obstructions, coaxial cable quality and length, and connections also affect performance. Check marine VHF band compatibility, mount and connector. Compare gain figures using the same reference (dBi or dBd). No gain rating guarantees a fixed range in nautical miles.