. The cruise ship MV Sweatpea is travelling in a straight line at constant speed so that it will pass a lighthouse at a distance of 500 m from the lighthouse. When the angle at the lighthouse between the boat's current position and its position at its closest point is 83, the angle is decreasing at 0.8/minute. Given that 1 nautical mile is 1852 m, determine the boat's speed in . '1 knots (nautical ml lgs). hour