Click here for Merit McCrea – WHEELHOUSE SCOOP

Wednesday, August 7, 2019

Currently speaking
Last week I covered a pair of online sources for water and weather conditions and forecasts. The next on the lineup of online map displays is SDSU's composite of high frequency radar data on current speeds. Incredibly, it is possible to see the surface currents across almost the entirety of the SoCal Bight, real time, hour by hour, all online.

Now, if you're not much of a skipper, the only thing you want to know is where someone else who caught a fish caught it. But those who have the hours on the water behind them really want to know all about water color, temp and current for as much of the area within their range as they can. They don't want to have to guess and go just to find out conditions aren't right, while some other zone they could have gotten to had good water and flow.

I can just about guarantee most don't know there's a way to see the flow all around Catalina island online before they even leave the dock – has it. The way these data are gathered is via a network of high frequency radar sites scattered up and down the coast, some at the islands and even down into Mexico.

They measure current direction and speed via what's called Doppler shift. Generally it sees the top meter of water or so. My experience is it's pretty darned on the money and continues to correctly capture the primary flow, even in windy conditions when whitecaps cover the surface.

Once on the website the controls are on the upper left. It does run on a phone but touch screen control can get a little quirky at times. On a laptop – never a problem.

When it first opens you'll see the entire world, with the US front and center. You'll notice the West Coast shows a colorful smudge along it.

Zoom in to SoCal and that smudge turns in to a field of arrows – vectors – color coded for the current speed. In the control section you'll see it's set for 24 hour average and speed is as cm/s by default – the standard units used in oceanography.

I turn off the 24 hour average and turn on all 4 resolutions under "hourly." I change cm/s to kts for knots.

Next, I change the map to "satellite" so I can see all the underwater features and banks.

As you zoom in to your area of interest you'll notice the arrows are in several different sets, one for each of the 4 resolutions, and sometimes the sets don't agree exactly. Also there may be holes in the coverage here and there.

That's the nature of raw real data, sometimes signals can be blocked and areas will lack coverage. Some data sets will be at slightly older than others so they won't exactly agree all the time.

For the most part, at least one of the 4 sets will have coverage where you're interested in the flow. For example, this morning I was able to see I needed to angle a little east on our way across to Santa Rosa Island, to avoid a north-bound jet. It was possible to know ahead of time there was a fairly strong easterly flow over the area we would be fishing and plan for it.

Next on the list of online info that's available is the "AIS" data. AIS is the "Automated Information System." Larger boats and ships are required to have some level of shipboard tracking system or AIS. What it does is it broadcasts the vessel's location, course and speed, along with the vessel's basic information, like its registered name and type.

Some smaller vessels have AIS voluntarily, or will have it automatically included as part of their electronics packages. For example, our UCSB Marine Science Institute's fleet of 3, 22-foot Andersons all have it.

There are two levels of AIS – one that's VHF marine radio based, and a second which bigger boats carry that's a satellite system. While VHF can be limited by distance and shadowed behind islands, the satellite system is global and high seas.

Between vessels at sea this info is received and plotted on the boat's chart plotter, so the pilot can see the names of the other boats and their positions and course. But the gist here is you'll find several websites online that plot these same data on a map, with coverage across the globe.

You can spy on the world's fleets from your armchair. This includes the larger vessels in our party boat fleet. The different websites offer different levels of access at no charge and for a membership fee open up even more options, like past track lines, full info on the satellite AIS boats and such.

Because there are several sites that do this, the best I can offer is to search "boat" along with "AIS" and check out what you find. Now, the fleet's not going to love that I put this out there, but all the "Parker" guys are already way up on this anyway and poach yesterday's hot spot, beating the fleet to the numbers the next morning.

For this reason, the smaller non AIS boats in the fleet are not eager to share with the big boats right away anymore, because they bring a rag-tag fleet of spot poachers with them wherever they go.

The way I see it, is it's like your cell phone. Short of refusing to do anything web based on your phone and leaving the thing at home, the data sniffers can basically retrace your every move and online action if any were ever to get the inkling to waste their life retracing yours.


In the meantime, we have heard back from DNA guy Dr. Matthew Craig at NMFS SFSC in La Jolla on the weird driftfish Greg Mayer caught in the surf a few weeks back. It was a 100-percent match to the longfin cigarfish ( Cubiceps paradoxus) and showed a 94 percent match with the Cape fathead (Cubiceps capensis) — clearly a close relative.

DFW environmental scientist Ed Roberts is the winner with the correct species.

At 42 pounds 50.5 inches it's the largest of these rare fish ever recorded.

* * *

Merit McCrea is saltwater editor for Western Outdoor News. A veteran Southern California partyboat captain, he is a marine research scientist with the Dr. Milton Love Lab at the University of California at Santa Barbara’s Marine Science Institute. He can be reached at:

•   •   •   •   •

We hope you enjoyed this article on our no-charge website Of course, this site contains only a small fraction of the stories that Western Outdoor Publications produces each week in its two northern and southern editions and its special supplements. You can subscribe to the print issue that is mailed weekly and includes the easy flip-page full-color digital issues, or you can purchase a digital only subscription. Click here to see the choice.

Reader Comments
Be the first to comment!
Leave a Comment
* Name:
* Email:
Website (optional):
* Comment:

Advertise with Western Outdoor News