Antennas

A lot of “landlubbers” that visit our boat are curious about all the antennas mounted on our cockpit arch. We didn’t install these all at once but have accumulated them over time when a need or new technology requirement arose. Follow along with the featured picture from left to right. Here’s what they all do:

TV – We used to have a much sleeker looking disc shaped “marine” TV antenna. It had a range of about 40 miles and was quite expensive. That antenna was one of the items torn off our arch in the Bahamas last year when a wayward sailboat side-swiped us while we were docked in a marina in Bimini. We decided to replace it with a much cheaper outdoor “house” antenna from Walmart. While not “marinized”, most of the parts of this antenna are not corrosion-prone and it was about 1/10th the cost of the previous one. In addition, this new antenna has a range of 70 miles which brings in all the HD “off-the-air” channels from Jacksonville, about 45 miles away.

GPS – This is our main GPS antenna (Garmin Model GPS 19x). It connects directly to the marine electronics data “bus” on the boat (NMEA 2000) and provides location information to all other devices connected to that same bus.

VHF – Spare VHF antenna. Our primary VHF antenna is on top of the mast, 60 feet up. In the unlikely event that our mast were to come down, we did not want to lose VHF communications. The wire from the spare antenna runs all the way to the back of the radio inside the boat but is not connected. If we ever need to use it, we just unplug the mast mounted antenna wire at the back of the radio and plug-in the spare antenna wire. Both our mast-mounted antenna and the spare on the arch do double duty with our Automatic Identification System (AIS) transceiver. Our AIS setup has proved invaluable in numerous circumstances and worth every penny of its cost. AIS uses the VHF radio band to transmit a boat’s name, size, location, speed, and bearing every few seconds. It allows us to easily identify/observe the boats around us (within about 20 miles) with much more detail than radar. However, while it is a requirement for all commercial vessels to transmit AIS information, it is optional for recreational boaters. Thus, we still need radar.

WiFi – Range extender (Model: Rogue Wave). This is much more than just an antenna. Within the silver-colored section at its base is a web server computer. An ethernet cable connects this antenna to our wireless router inside the boat. That same ethernet cable also delivers the necessary electrical power to the antenna to run the web server embedded in its base. Once the little server in the base of the antenna boots up, it searches for all the available WiFi signals up to 5 miles away. From a computer inside the boat, we can login to the antenna’s web server and choose which signal we want to amplify and send to our router. The WiFi signal we choose has to be unencrypted, otherwise we need to know its password. This works best for connecting to a marina’s WiFi when we’re in a distant slip or out in their mooring field.

GPS – Dedicated GPS antenna for Chartplotter at helm. In the event our marine electronics bus suffers a complete failure and/or the main GPS antenna described earlier stops working, this GPS antenna connects directly to the Chartplotter at the helm station. In our normal mode of operation this antenna isn’t used and is only there as a backup capability.

Radar – 18” Diameter, 4kW Power, Range: 36 Nautical Miles (Model: Garmin GMR 18 HD). We use the radar mainly at night to “see” other vessels around us. As many boats are now transmitting an AIS signal, we often can “confirm” a radar contact with its corresponding AIS contact. The radar is also useful during all hours for tracing nearby rain/storm cells.

Sirius/XM – NMEA 2000 satellite receiver (Garmin Model GXM-51). We originally got this antenna to take advantage of the satellite-based marine weather service offered by Sirius/XM. We wanted a reliable way to receive up-to-date weather information if we were beyond the range of Cell/VHF/WiFi signals. This proved to be very disappointing. The antenna connected to the satellite just fine, but the weather information transfer was agonizingly slow. When we finally did get it, it usually proved to be inaccurate based on what we were experiencing directly in front of us. We discontinued the service. On the other hand, this antenna was also capable of receiving all the Sirius/XM music channels, a function at which it excelled. We can use our Chartplotter to select the different music channels and pipe the music through to the boat’s stereo system. There is a small monthly fee for this, but it works great.

Anemometer – Ultrasonic wind sensor (Maretron Model WSO100). When we first got the boat, the previous owner had installed a traditional anemometer on top of the mast – the kind with the spinning cups. When hurricane Sandy came up the Chesapeake Bay ( we were there at the time), the strong winds damaged the anemometer. We decided to replace it with this ultrasonic model that has no moving parts. When we first did this, we mounted it on top of a small pole that extended above the Radar dome. It remained there for several years. Then last year in the Bahamas the ultrasonic  anemometer and the pole it was mounted on were both torn off the arch in the same incident with the wayward sailboat described above that destroyed our TV antenna. The ultrasonic anemometer you see in the picture now is a newer 2nd unit we had to buy. Its new mounting location isn’t as ideal, but still works well enough. It also measures air temperature, humidity and barometric pressure.

GPS – Dedicated GPS antenna for Chartplotter at Nav station. This antenna serves the same purpose as the backup GPS antenna for the helm Chartplotter mentioned above, but is instead connected directly to our 2nd Chartplotter at the navigation station inside the boat. Once again, in our normal mode of operation this antenna isn’t used and is there as a backup capability.

Cell Phone – 3G/4G Cell signal amplifier (Model: weBoost Drive 4G-M amplifier, Antenna: Wilson 4G omni-directional marine antenna). This setup, which includes a small amplified unit inside the boat, is meant to be used inside a car to boost a weak cell phone signal when driving in rural areas. We hoped it might work just as well on the boat. We purchased a larger “marinized” antenna to use in place of the short little magnetic antenna that came with the amplifier which was meant to be mounted on a car roof. While in the Exuma island chain in the Bahamas, this device worked beyond our wildest expectations. We were able to have a connection to the Internet via cell signal everywhere we went. This is the device that enabled us to post both articles and pictures to our blog site every single day while cruising these islands. While it is advertised as being compatible with the US-based cell networks (Verizon, AT&T, T-Mobile, Sprint), it worked just fine on the BTC cell network in the Bahamas. We mainly used it to make one of our cell phones a “hotspot” to which our computers connected for Internet access.

SSB – A 50’ section of our port backstay is electrically isolated from its top and bottom connection points and used as an antenna for the single sideband radio. We mainly used this capability to receive weather forecasts early each morning from Chris Parker’s weather forecasting service. It worked well enough to give us another reason for not needing the Sirius/XM weather service. This also gives us the ability for long range radio communications.

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