Marine Antennas Our marine antenna line-up is an extension of our XL series Base Station Antennas. Many of our Unity Gain Base Station antennas are available as Marine antennas. They are generally supplied with a triple chrome plated 1”- 14 Thread standard marine sleeve. This sleeve mates with most standard marine mounts. Since water provides a great conductor of RF signals, and the narrow beam width of gain antennas doesn’t work well because of the normal swaying of a boat in water, we typically do not recommend gain antennas for marine application. We also supply Marine Mount antennas for applications where a crank down version of this mount is used on swat type or mobile communication center vehicles. In this application, the vehicle is driven to a site with the antenna cranked in a down or horizontal position, and raised up for use while the vehicle is stationary. In this application a gain antenna is often acceptable.