Rose Point Coastal Explorer 2009 brings AIS targets to life

[This article appeared at MadMariner two weeks ago. Tomorrow morning a new Navagear item will appear on the front page of MadMariner. —Tim]

I haven’t yet had a chance to take the boat out with the newly released Rose Point Coastal Explorer 2009. But I did get down to the boat to determine if my current AIS installation would work with the new software.

Good news: It works! It’s actually “plug-n-play,” which is amazing. So many things are touted as plug and play, but I’ve found the reality far from satisfying with most marine technology.

But this time, I literally plugged my Shine Micro RadarPlus AIS-BX Class B AIS transceiver into my laptop (via a Keyspan USB-to-Serial Adapter) and asked Coastal Explorer to auto-detect ports. It found the port with the NMEA traffic, and from then on everything worked fine. I’m probably a little bit luckier than most, because my Class B AIS unit already has its own GPS, so I didn’t need two ports (one for GPS data and another for AIS data). All the data I need comes in over one pair of wires, and the 9-pin connectors were compatible.

Since I wasn’t going anywhere, I devoted today’s session to Coastal Explorer’s handling of AIS targets. I love AIS. With Coastal Explorer, AIS is really cool. I know, I’m a geek; but hey, at least I can admit it.

Take this chunk of screenshot, which shows the Ship Canal between the Ballard Locks (upper left) and Foss headquarters. Notice how most of the AIS targets (the blue triangles) are all the same size. Well, almost all. Any targets for which overall dimensions are known and which are actually larger than the default blue triangle (at any particular zoom/scale setting) are depicted with the target’s actual (scaled) dimensions. See the long thin one tied up just outside Fisherman’s Terminal, right in the middle?

Oh, you’re not sure you see it? Take a look at the zoomed-in image.

There it is: Mt. Mitchell. Notice more vessel names appear as we zoom in, and more vessels are depicted with a polygon other than the default triangle.

Lordy, how I wish my old-school Raymarine C-80 would do this. In actual practice, it’s extremely handy to know which vessel is the biggest, because that’s probably the one you’re genuinely worried about.

But one side effect of Coastal Explorer’s accurate depictions of the available data is that it reveals inaccurate AIS data. For example, I’m doubtful that American Dynasty is really 30 meters long and 70 meters wide. Call me a skeptic, but I just don’t buy it.

There are lots of AIS display options you can control, too. For instance, here are the vessel display options under Tools>Options>AIS:

•Show Tracks (you can specify the track length, in minutes)

•Show Predictors (uses the same length of time as your own vessel’s predictor-vector)

•Show Vessel Names

•Show Vessels with Class B AIS Equipment

•Show Dead Reckoned Position

There are several other AIS options, as well, toggling the display of other types of targets, for instance, and establishing thresholds for determining “dangerous” targets. This is a combination of two variables: Closest Point of Approach (CPA) and Time to Closest Point of Approach (TCPA); “Targets are considered dangerous when they will be closer than the Danger CPA distance within the Danger TCPA time.” Users need to determine what these values should be, based on the conditions and the vessel’s maneuvering characteristics.

One feature that’s fun to watch is “Show Dead Reckoned Position.” With Class A targets, the known position is updated every few seconds, but in between updates, you can watch the dead reckoned position march across the chart, a “ghost” of the AIS target shape moving along in real time. If you’re confused about dead reckoning, in this case it just means that Coastal Explorer is taking the vessel’s last known position, course, and speed, and extrapolating where the vessel should be, assuming none of those parameters have changed. As soon as an update is received, the primary target triangle is moved to the new position and the dead reckoning ghost disappears. Wow, “the dead…ghost…disappears.” I better not tell my kids about this; they might have nightmares.

Another note about the dead reckoned position: with Class B AIS units, like mine, new position/course/speed data is only transmitted every 30 seconds. So the dead reckoned position could be extremely helpful. The flip side is that it could also be extremely inaccurate. After all, I can turn on a dime, and I often do. It’s a character flaw, probably, but that’s a topic for another day. The point is that each vessel operator is going to configure Coastal Explorer to present the information they want, the way they want to see it.

Here’s another feature, related to the dead reckoned position. In this screenshot, you can see the predictor-vectors (six minutes, as currently configured) for several vessels underway in Elliott Bay.

 

The tugs Chief and Guard are helping Hyundai Republic get underway. Tug Guard is going to intercept Shelley Foss‘s path, but Shelley Foss is moving so fast she’ll be long gone before Guard even gets close. Chief and Guard have started spinning the big auto carrier to get her nose pointed out of Elliott Bay—you can tell by the way the predictor vectors are starting to spiral.

Note that for some reason, Hyundai Republic‘s vessel size data hasn’t been received, or else it’s inaccurate. During this session, Coastal Explorer never did display her with anything other than the default AIS target triangle. It would be a lot easier to understand what’s happening if Hyundai Republic were transmitting accurate vessel dimensions.

But in case you were worried, all the little triangles got where they needed to be, and none of them collided. All thanks to AIS. Well, that and good boat handling all around.

So far, I am absolutely delighted with Rose Point Coastal Explorer 2009, and I haven’t even untied the boat from the dock. Stay tuned to Navagear for some genuine underway testing.