The captain of a boat wants to travel directly across a river that flows due east with a speed of 1.48 m/s. He starts from the south bank of the river and wants to reach the north bank by travelling straight across the river. The boat has a speed of 5.64 m/s with respect to the water. What direction (in degrees) should the captain steer the boat? Note that 90° is east, 180° is south, 270° is west, and 360° is north. In this problem, we were told to find the answer by taking 360 minus the inverse tangent of windspeed/boatspeed. I don't understand why the 'boatspeed with respect to the water' should be perpendicular to the shore. It seems to me that since the water is moving, the the 5.64m/s with respect to the water should be the hypotenuse of the triangle. What's wrong with my thinking?