Class A and Class B are the two main divisions. Class A AIS devices are primarily intended for use on large commercial vessels. These units operate at high power and provide very frequent updates. Class B devices, on the other hand, are aimed at smaller vessels such as yachts, fishing boats, or commercial crafts. They provide a cost-effective, low-power, yet reasonably effective solution.

When making your selection, consider the size of your vessel, your budget, and required system compatibility. Opt for recognized brands known for delivering dependable support and product enhancements. Ensure that the AIS device you select supports the type of interfacing used in your boat’s navigation system, such as either the NMEA 0183 or NMEA 2000 interface.

Equally important is the choice between standalone AIS transponders and combined units integrated with chartplotters. Standalone devices provide the flexibility to connect with multiple sources of electronics, whereas integrated units simplify your digital constellation by merging AIS with GPS and charting functions.

 

Plan the Installation Location

Start by finding a dry, ventilated, and accessible area for the AIS unit itself, usually inside the cabin near other electronics or navigation stations. Avoid places with extreme heat or moisture buildup since these can damage electronic circuits.

The VHF antenna should be installed on a high point of the vessel’s mast or a dedicated antenna pole. The higher the antenna, the better the AIS range will be, so it’s important to understand that AIS uses line-of-sight radio signals. Make sure the antenna has a clear view of the horizon and is away from other antennas or metal objects that could cause interference.

The GPS antenna also must be mounted outside the cabin, away from large metal structures in order to get an unobstructed signal from the sky. Some AIS units have integrated GPS antennas, but if yours does not, mounting a separate GPS antenna properly is essential for accurate vessel positioning.

Take your time at this stage to sketch a rough layout or map where you plan to place each component. Think about cable routing to minimize exposure to damage and ease of maintenance later on.

 

Mount the Antennas

For the VHF antenna, use non-conductive mounts made specifically for marine antennas. Secure it tightly with bolts or clamps that can withstand vibrations and bad weather. 

Marine-grade coax cable should be run from the antenna down to the location of the AIS unit on board the vessel. Do not let the cable make sharp bends, and secure it with cable ties. Seal any entry points where the cables pass through the deck or bulkheads to prevent water from entering.

If you are using a separate GPS antenna, mount it where it can see the sky well and away from possible sources of interference. Run the GPS antenna cable carefully toward the AIS unit, again sealing any holes or gaps so as not to compromise the integrity of your boat.

Give the antenna a little shake to make sure it is tightly secured. Use a multimeter or antenna analyzer, if you have one, to check cable continuity and signal reception.

 

Mount the AIS Unit

With antennas securely in place, install the AIS transponder inside your boat. Ideally, mount it near other electronic devices like your chartplotter or VHF radio for easy integration. Attach the brackets or use screws as directed in the device manual.

Make sure the AIS unit has space around it for ventilation and is protected from water splashes. Also, leave room to access connectors and DIP switches, or buttons needed for configuration.

Label or mark cables running to the AIS unit for easier troubleshooting and future upgrades. Proper cable management not only creates a neater look but also protects cables from accidental disconnections or wear.

 

Wiring and Power Connection

The majority of AIS units are designed to operate on 12V DC from your vessel’s battery system. Locate your main electrical panel and pick a suitable circuit breaker or fuse to safeguard the AIS.

From the power source to the AIS, run one positive (red) and one negative (black) power wire. Use marine-grade wire of an appropriate gauge suitable for the current draw specified by the AIS manufacturer.

Placing an inline fuse close to the power source’s positive terminal is essential to protect against short circuits.  Use fuse holders that have the proper rating for your AIS unit.

Attach the power cables to the AIS device, making sure to match the correct polarity. Use crimp connectors or solder joints covered in heat shrink tubing to make secure and watertight connections.

If your AIS requires interfacing with navigation instruments, run NMEA cables or connectors between the AIS and other electronics. This step allows your chartplotter or multifunction display to show vessel traffic based on AIS data.

After wiring, double-check all electrical connections with a multimeter to ensure proper voltage and no shorts.

 

Initial Power-Up and Configuration

Turn on your boat’s battery or main power supply, followed by powering up the AIS device. Consult the user guide to input your vessel information, including the MMSI (Maritime Mobile Service Identity), boat name, call sign, and size specifications. The MMSI is a special identification number, which you get from the maritime authority in your country, and it is necessary for AIS communications.

Make sure your GPS antenna is receiving a strong and unobstructed signal. Wait for the AIS to take satellite position before proceeding. A lot of units show this status through LED lights or display messages on their screens. Set the transmission parameters of your AIS according to your vessel class and local rules. While most units will automatically regulate power output and message rates, checking will help prevent interference or violations.

If your AIS unit is connected to your chartplotter or another navigation display, set the correct communication protocol (NMEA 0183 or NMEA 2000) and baud rate. Then activate AIS display capabilities in your chart software so that you can view other vessels in real time.

 

Testing and Verification

First, notice whether the AIS is transmitting properly. Search for the boat’s name or MMSI on an AIS smartphone application or an online vessel tracking website and see if it presents your boat.

Then look at the reception in your area for other vessels. If your chartplotter or AIS display presents ships near you, your antenna installation and reception are working well.

Check the AIS display for warnings or errors. If you see very weak signal transmission or no GPS fix again diagnose wiring and antenna position.

Also try to get feedback from other boats or marina staff with AIS equipment that your vessel appears on their screens.

Do test runs in open water to make sure AIS consistently works under operational conditions. Be patient – some systems improve location and settings after a few minutes of use.