Digital Antenna 598-SW-S 8 AIS Marine Antenna w/25 Cable [598-SW-S]598 SW S 8' AIS Marine Antenna w 25' Cable Designed to meet the exacting AIS frequency requirements and in conjunction with the USCG Automatic Identification System (AIS) requirements for commercial vessels, Digital Antenna created a series of 8' AIS antennas that provide a low 1. 5: 1. 0 SWR ratio from 159 162 MHz. These 4. 5dB gain AIS antennas offer unsurpassed durability and performance and are compatible with all AIS transponders. Customers and