Why choose omnidirectional fiberglass antenna on board the ship

When building a wireless communication system on a ship, multiple antennas are required, such as satellite receiving antennas, GPS positioning antennas, and VHF maritime walkie talkie receiving and transmitting antennas. And most of these antennas use omnidirectional fiberglass antennas. Why use it and what are its features? Today, I will talk to you about this omnidirectional fiberglass antenna.
Firstly, what is an omnidirectional antenna and what is the vertical angle.
The omnidirectional antenna commonly referred to in the construction of wireless antenna systems refers to an antenna with a degree of radiation angle of 360 degrees, which emits in a fan-shaped manner vertically. The angle is usually around 6-15 degrees, and the higher the gain, the smaller the vertical angle. For example, a 9dB antenna can achieve a radiation angle of about 14 degrees, while a fiberglass antenna can reach around 8 degrees, which was once the limit. Due to the small vertical angle, fiberglass antennas are commonly used for wireless masking in open sea war zones. When mounted higher, such as on a ship's mast, they can transmit the transmission signal to a farther center and achieve greater communication spacing.
Secondly, why is fiberglass antenna not suitable for indoor use, but for outdoor spaces such as ships.
Many people may have noticed that most antennas are labeled with 2dB, 5dB, and 7d, and it is rare to see indoor antennas with 9dB or better gain. According to our common understanding, for indoor use, the 7dB antenna has fully met the requirements. Antennas with a 7dB or higher angle may not be able to exert their advantages due to their smaller angle, and indoor use may have the opposite effect. Therefore, omnidirectional antennas with a bandwidth of over 9dB are definitely recommended for outdoor use. As for some people who say that indoor use has good wall penetration effects, this statement cannot be verified, so there is no need to be overly confident. Also, the material of the fiberglass antenna prevents it from being easily corroded by rainwater and has good toughness. Therefore, the environment in which maritime walkie talkies are located determines that they must use fiberglass antennas.