Your VHF Antenna is a critical component of your boat's VHF instllation and comprehending exactly how they work will help you make a more educated purpose on which VHF antenna is best suited to your specific requirements. The right antenna can greatly increase your ability to communicate with other boaters or people located on shore. The core purpose of a VHF antennna is to be a radiator for the power that the radio transmitter produces and direct this energy in the appropriate direction to maximize ship to ship and ship to shore communications. You should make sure that your antenna is protected from weather by an enclosure or is made of materials that will resist corrosion in the marine environment.
dB Rating / Antenna Gain:Antenna gain or db rating refers to the amount of transmitting power that is increased by the antenna's energy focus. Antennas with a higher db raiting or "gain" concentrate energy on a perpendicular plane to the shaft of the antenna in an energy field that is disk shaped. This energy concentration enhances the strength of your radio to surrounding vessels and communication stations.