This allows you to test different scenarios and strategies for crossing the Gulf Stream (or other current) by boat. Look here for an explanation of the different strategies that appear below.
Up to five different strategies can be compared at once. Consider the origin, (x,y) = (0,0), to be the starting point of the trip, and assume that all trips are to the east (x increases as the trip proceeds). All scenarios use the same east/west distance to the destination (the x-coordinate of the destination), but the other inputs are allowed to vary from scenario to scenario. All units are in nautical miles for distance, knots for speed, and hours for time.
In each case, the first set of inputs specifies the current by dividing the total east/west distance into strips, with a different current and boat velocity in each strip. All currents are assumed to flow directly north (positive current velocity) or south (negative current velocity). The inputs allow for up to 10 different strips of current. If the total width of currents specified is greater than the east/west distance to the destination, then the "extra" current is ignored. If the total width of the currents is smaller than the distance to the destination, then it is assumed that there is no current as the boat nears the destination.
The information here is meant to be educational. It is not a substitute for prudent and informed decision-making. As much as I've tried to get this right, the numbers here could be totally wrong. In fact, they will be wrong. Any model is only a crude approximation to reality.
Total east/west distance to destination (used for all cases):
After supplying the inputs The graph or table below shows the position of the boat, the total time taken or the heading, depending on which of the tabs on the left is chosen.