To choose a VHF antenna, you should take its size, gain and cost in consideration and keep them balance. Using which type of antenna is based on the distance needed, physical requirements and cost. If you want to get good VHF coverage, an antenna is of great importance. An expensive radio will be meaningless if it is not connected to a good antenna. The height of the antenna off the water is also a main factor when choosing. Generally the higher the antenna is, the better the range or coverage will be.
VHF radio runs in a straight line and is named as sight line. Coverage is affected by the curvature of the earth and any barriers between the two radios. Two stations trying to communicate between each other will not be able to do so when they both fall below the horizon and cannot be "seen" by each other. Due to the curvature of the earth, best case VHF communication is normally limited to about 35 - 45 miles.
Since height is a major factor in range, sailboats can easily get better range by mounting the antenna at the top of the mast together with a suitble antenna. Small power ships are always just a few feet off the water, so installing a high antenna is not practical.
VHF radio runs in a straight line and is named as sight line. Coverage is affected by the curvature of the earth and any barriers between the two radios. Two stations trying to communicate between each other will not be able to do so when they both fall below the horizon and cannot be "seen" by each other. Due to the curvature of the earth, best case VHF communication is normally limited to about 35 - 45 miles.
Since height is a major factor in range, sailboats can easily get better range by mounting the antenna at the top of the mast together with a suitble antenna. Small power ships are always just a few feet off the water, so installing a high antenna is not practical.