Waste of Pi. Probably. I learned on Haida Gwaii that Canada Government knows nothing of tides. Best predictor you make yourself, you observe the local High Tide and then make SIN-curve with six hours and 12.5 minutes cycle. You combine this with local sun SIN-curve, and when those oppose you have a MASSIVE tide and when they meet you have a HORROR tide. This is important because the bloody rainforest grows to the edge of the beach and little bit over. At HORROR tide you must camp in the forest with snakes, bears and snails.