What’s the scariest aspect of cruising? Is it piracy, deep water, close land, or foul weather? For me, none of these are as terrifying as midnight encounters with big boats. These tankers, cargo ships, and cruise liners are huge, fast moving, and often piloted by guys whose first language ain’t English. We haven’t seen many in the Bahamas, but we hear there is a lot of shipping traffic in the Yucatan channel. So it’s a bigger concern this trip.
First you see a quick blink on the horizon. Then the light(s) get brighter. As you toss around, you measure their progress relative to some point on your boat. If they appear stationary you may be on a collision coarse.
Now our boat had radar. It could help in situations like this, but it used a lot of power. And the display was comparable to that of the CRT you first programmed to print “Hello World” using BASIC.
Automatic Identification System (AIS) is the current way to address boat tracking. Using VHF radio signals the AIS will track and display boat icons and directional arrows on your GPS/chart plotter. You can easily see how to avoid big boats. And if you do need to chat, you can select the boat to get its name, heading and speed.
Boats over 300 tons are now required to transmit AIS information. We just want to receive. In AIS terms this is called running in pirate mode.
To install receive-only AIS all we needed was an AIS receiver and a splitter for our VHF antenna (which is mounted at the top of our mast). Oh, and one other thing. Our chart plotter had to be current enough to receive AIS signals. Ours wasn’t even close.
I found a reasonably priced splitter/receiver combination online, then started shopping for chart plotters. It seems that plotters are becoming the entertainment centers of the boating world. In addition to super CHIRP Sonar graphics that will show you a dime on the ocean floor, they have wireless access, can play music, show movies, call other boats, and do lots of other stuff we don’t care about.
After reviewing nine brands our search was reduced to two. We went to a store to check them out. First we looked at Raymarine, the Ford of cruising. All of our old instruments are Raymarine. It was very nice. It had familiar charts and a pinch-to-zoom interface.
Then we tried a Garmin, which is a cut above. It was over in minutes. As we left we just kept telling each other “It’s just a few hundred dollars more. And we’ll use it all of the time”.
I installed the components in Indiantown. No AIS boats showed up on the plotter, though. None showed on our trip to Ft. Myers either. This isn’t a shipping port, but I began to get concerned when none showed after a few days. One morning I heard a huge horn blast. I saw a boat pull out of a marina and knew that it must have all the latest gadgets. I powered up, rechecked my settings and tried a change. Soon I could see lots of AIS boats nearby. Now we are are ready for those shipping lanes.