Force 2 from "Local Knowledge" - 2006 Worldwide Edition |
Many of the world's popular sailing venues exhibit strong currents. Unless a navigator takes these into account accurately, computations of headings, times, laylines, etc. can be substantially in error. This can be a matter of safety for the general mariner, or a competitive edge for the racer. For the casual cruiser it can make the difference in planning a realistic itinerary and arriving ontime. Unlike every other program, Local Knowledge doesn't just put tidebook data onscreen. We use all available data to build a mathematical model of currents at every point in a region, and incorporate our current models into all navigational and tactical computations. We do not use averages in our course computations, but search out courses point by point and moment by moment to find the route that compensates properly for current. Other programs either ignore currents, or show then only at discrete, widely separated points. NO OTHER PROGRAM PROPERLY CORRECTS FOR CURRENT. |
| San Francisco Bay Currents. This display option shows digital values for current magnitude and streamers for direction. The blue points are comparable to those found in other programs. The yellow points have been added by this user for more detail. Force 2 calculates current at every point, so you can add as much detail as you like, and save your sets of added currentpoints for recall next time. |
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| Alternative vector display: currents at the entrance to Chesapeake Bay. You can display magnitude at a point by simply moving the cursor. The cursor can also display latitude and longitude and range and bearing from the boat to that location. |
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| For the sailboat racer or cruiser, Force 2 can also display current corrections to a layline. Below, in Admiralty Inlet, the solid blue lines are the laylines in the absence of current, and the dotted magenta lines are the actual laylines taking current into account. Force 2 automatically includes current effects in computing heading, time and distance point to point, and can compute and compare courses of multiple legs to determine which is the fastest. It has an easy-to-use "point and click" course building utility, hooks to your GPS and includes a broad spectrum of nav functions. |
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| Force 2 can be used live, updating currents automatically, or to study currents and courses in advance. It is also a useful tool to teach sailing and navigation or improve your own skills, including the ability to speed time evolution up to 1000x to see how currents and boat positions change over time. The graphic below shows a simulated motion from point 1 to 2 on a constant (rhumbline) heading at 6 knots. Due to the strong flood current, the boat is driven north to the point shown. To avoid this, the program will compute a heading which corrects for current so you can arrive precisely on the mark. Although not primarily for navigation, Force 2 has a number of features that assist you. The points marked "L" are locations of landmarks (points of land, etc) on which you can click to help identify where you are, and you can click on the buoy symbols to display their name, type and signal. |
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| Force 2 has many other functions and features. For more detail see the links on our Local Knowledge "goflow" home page at www.goflow.com. Force 2 is now available at a long list of venues around the U.S. and abroad. Our current model for the Hauraki Gulf was used by Team New Zealand in the last Americas Cup, and our model for the English Channel in the Fastnet Race, among many others. |
| Once
a user has Force 2, coverage for other regions can be purchased as an add-on. Force
2 comes with a single region for $200, and add-ons are $100 (add $75 for non-US regions).
All regions complete with charts, specially edited for clarity. We have many other products and services. See our Download Page for DEMOS. |