Most people think that a boat that points 5 deg worse than another has to make up the 5 degree difference in distance. It is substantially worse than that. Because the effect of speed on apparent wind varies with apparent wind angle - and this is a rapidly varying function at around 40 degrees - the VMG loss is more that just the difference in pointing angle. Comparing two boats, one points at 28 apparent, another at 33. in 10 knots true wind, the 28 degree boat will have a VMG of 4.76 at 7 knots. A simple ratio of apparent wind cosines predicts that the 33 degree boat will have a VMG of 4.5 knots. However their true wind angles differ by more (47.2 to 55.4, over 8 degrees), and the 33 deg boat will have a VMG of only 3.97 knots.