Please select your home edition
Grapefruit Graphics 2019 - Leaderboard

Tips for installing AIS on your boat

by Jeff Cote 12 Jul 08:31 UTC
Automatic Identification System (AIS) © Jeff Cote

AIS stands for Automatic Identification System and that is exactly what it does. When asked about AIS, we often use the example of exchanging virtual boat "business cards" on the water.

AIS information includes the vessel name, call sign, vessel size, and navigation data such as present location, course on ground, and speed on ground. AIS information can be used on its own, but most often the information is displayed on your boat's chartplotter by overlaying each AIS target's physical location, Course Over Ground (COG), Speed Over Ground (SOG), and other information in relation to your position and COG. Some chartplotters will even predict potential collisions and warn the operator. Since AIS information is transmitted over VHF frequencies, it does better than line of sight, and commonly is able to receive AIS broadcasts over low mountains or islands. Unlike radar, AIS can effectively "see" around corners. This can be a huge safety benefit in inclement weather or when navigating the many islands and passes of the Pacific Northwest, and it is a great complement to your existing radar. Also, because AIS includes the vessel's MMSI number and name, hailing a particular ship over VHF can be simplified.

An MMSI number is like a phone number for your boat. When a boat changes hands, you must fill out an application to register the change of ownership to ensure that Coast Guard has the correct emergency contact information.

AIS is a fully automated tracking system used to identify and track other vessels visually, as a method of collision avoidance. Passenger ships, such as ferries, tugboats and most large commercial vessels, have a Class A transceiver (12 watts), to send and receive AIS information on VHF frequencies. Some recreational boaters opt to transmit AIS information using a Class B transceiver (2 watts). AIS information is free and no subscription is required. All you need to take full advantage of AIS is a VHF or AIS antenna and AIS receiver (and/or transceiver), plus a compatible chartplotter or smartphone/tablet.

Most major chartplotter manufacturers have their own AIS components, today we are going to look at the Vesper Marine WatchMate XB-8000 smartAIS transponder with Wi-Fi and an NMEA 2000 gateway. One of the unique things about this product is that you can use it even if you don't have a chartplotter. The WatchMate App allows you to monitor navigation data, AIS and GPS alarms from your mobile device over a local Vesper Wi-Fi network. The XB-8000 will transmit your position over radio frequencies every 3 minutes when your speed is under 2 knots or every 30 seconds otherwise and your vessel information is transmitted every 6 minutes.


The Vesper WatchMate XB-8000 receiver is small, which makes is easier to interface with your chartplotter and requires minimum wire runs. Remember to write down the Serial Number from the unit before you install it, as this is required to set up the Wi-Fi.

Let's take a look at the connections required; power, an AIS or VHF antenna and the GPS.

  • Power - A 5 foot power cable with attached 10 pin plug is supplied with the XB-8000; you may extend this cable if necessary. When attaching the cable ensure you fully engage the locking ring to make a watertight seal. Always use a 2A fuse or circuit breaker; do not connect directly to the battery and if you must extend the power connections, use high quality pre-tinned marine grade wire, which is at least 16AWG.
  • AIS/VHF Antenna or a VHF Antenna with a splitter - The AIS system uses two special "data only" channels in the VHF frequency range, so almost any VHF antenna can be used to receive and transmit AIS data. The problem is that both the AIS and the VHF antenna should be installed at the highest point of the boat. However, if you choose to install two antennas, they must be a minimum of 5 feet apart otherwise all of the 25W power of the VHF will go directly into the AIS receiver and damage it.
If you would prefer to use your existing VHF antenna, make sure it has a vertical radiator, an antenna gain of 3dB or similar and an impedance of 50ohm. In the past, boaters preferred to install two antennas instead of an antenna and splitter because the reception was compromised on both the VHF and the AIS. That concern has been eliminated with new technology. As far as a digital splitter, we recommend the Vesper SP160, which is designed specifically for use with Vesper Marine AIS transponders. It has connections for AIS, VHF, AM/FM radio and requires an external power source.

Use the the WatchMate App to view the satellite signal strengths to determine the best location to mount the GPS antenna.

If you are a competent DIY'er with basic wiring skills, this should be a 6 - 9 hour installation. AIS is a great safety tool for any boat and works as a good addition to radar alone. The Wi-Fi capability allows everyone onboard to use a smart phone or tablet to follow along on the journey. Combined with the ability to transmit, it allows you to see and be seen.

This article has been provided by the courtesy of Bluewater Cruising Association.

Related Articles

Sailing in Chile: Part 1 - The journey begins
We were ready for a "quiet" sailing season After a "big" year of sailing from Guaymas, Mexico (27oN) to Valdivia, Chile (40oS) via the Galapagos and Easter Island, we were ready for a "quiet" sailing season. Posted today at 2:51 pm
Provisioning Tip: Do you know Nido?
Reconstituted Nido is almost as good as UHT milk When travelling for extended periods or in remote areas, fresh dairy products become unobtainable. In Mexico and Latin America, UHT processed milk (long-life box-milk) is widely available Posted on 15 Sep
Ready, Aye, Ready!
Sailing Avant in Mexico and Central America: Do you feel safe? We have been sailing Avant in Mexico and Central America for six years now, and one of the most common questions we get is "Do you feel safe?" Posted on 1 Sep
Singapore to Sri Lanka
Continuing to follow the adventures of Argonauta I In the last article from Memories of a Circumnavigation, Hugh and Heather explored the Java Sea and had some amazing encounters with orangutans. Posted on 25 Aug
The return of Sea Turtle!
Celebrate the conclusion of Jordan and Judy Mills' circumnavigation aboard Sea Turtle On July 3, approximately 30 excited family and friends, including many BCA members, gathered at Ogden Point with air horns, whistles and other noisemakers to celebrate the conclusion of Jordan and Judy Mills' circumnavigation aboard Sea Turtle IV. Posted on 7 Aug
Postcards from a Caribbean Winter part 9
Rod arrives in the Canary Islands The land was stark. The only colours we could see were earth tones of sandy beige, with brown rocks and sandstone cliffs as Oh! approached the anchorage at the south end of Graciosa Island. Posted on 30 Jul
First Aid Kits for Cruising
We looked carefully at what we would pack for first aid preparedness We could easily imagine a wide range of scenarios where one or the other of us, or another cruiser or local, was injured (grievously), and needed first aid in an inconvenient, remote location. Posted on 26 Jul
May long weekend Rendezvous at Poets Cove
Being boatless and living in Canmore can make it a little tricky to orchestrate Being boatless and living in Canmore can make it a little tricky to orchestrate as much time on the water as I'd like. So, when my daughter extended an invitation to join her aboard Easy Rider Posted on 22 Jul
Medical Insurance: To have or not to have?
Mike and Jacquie Champion catalog their experiences From La Cruz, we traveled the 11 miles to Nuevo Vallarta, put the boat into Paradise Village for a month and headed back to Vancouver for a week to celebrate my Mom's 85th birthday. Posted on 21 Jul
Electric dinghy engine update
New battery technology It's been a few years since we reported on our new electric dinghy engine (December 2012 Currents). We have updates to share and some observations about a new battery technology Posted on 20 Jul
Vaikobi 2019AUG - Footer 1B&G 2019 Q3 Cashback 600x600Grapefruit Graphics 2019 - Footer