Currents animation
The Currents button draws moving arrows or streaks that show which way the water is moving and roughly how hard. They look a little different on a phone and on a laptop.
Forecast every 3 hours; Observed daily
More detail
What the streaks are. They picture the flow at one moment. Each has a bright head and a fading tail and runs the way the water is moving. Following one does not tell you where bait, a weedline or anything else will drift.
How to read them. Long, quick streaks mean harder-running water. If the streaks barely move inshore or at the turn of the tide, the water really is slack. How fast they look also depends on your particle settings. For a speed in knots, put up a current layer from Data Layers. Those color the water by speed and show no direction.
The picture looks finer than the data is. On the Forecast tab the current behind it has cells about 5 nautical miles across, and on the Observed tab about 8, so small curls and swirls come from the drawing and are not real features. The Currents (button) article explains which current the button follows on each tab and at each depth. The streaks cover the Gulf of America, the East Coast and Baja only.
The particle settings. With Currents on, a small wrench appears above the button and opens a panel of sliders for how the streaks are drawn. On the iPhone app the "Min speed filter" hides slow water once you raise it. The app keeps the settings between sessions. If the streaks look wrong, or have stopped where the water should be moving, tap "Reset to Defaults" in that panel.
On a phone. The animation uses battery and can warm the phone. Turn Currents off when you are not reading it. On the iPhone app, after you move the map, part of the screen can be empty for a moment.
Who makes it. The streaks are RipIQ's own drawing. The current data under them comes from the Copernicus Marine Service, the European Union's ocean data service, on the Observed tab, and from HYCOM (U.S. Navy model) on the Forecast tab.
The numbers
| How often it updates | Once a day on the "Observed" tab, where the map opens; every 3 hours on the "Forecast" tab |
| How fresh it usually is | "Observed": about a day behind. "Forecast": the newest frame is from a run started between one and four days ago |
| How detailed it is | About 5 nautical miles per cell on "Forecast", about 8 on "Observed" |
| Where it covers | Gulf of America, East Coast and Baja only |
| Observed or modeled | Satellite-observed on "Observed"; modeled on "Forecast" |
| What you see on screen | Moving arrows or streaks giving direction and a feel for speed |
Source: computed by RipIQ from the DUACS satellite altimetry current on the Observed tab, and the HYCOM model current on the Forecast tab.