Long description

This is a chart showing the variation in tide height over 1 week from 7 to 13 October. The variation in height is roughly sinusoidal in shape, with a period slightly over half a day (the graph starts at ta trough and covers just over 13 cycles. The range from peak to trough increases over time. This is the neap tidal range at the start and spring tidal range at the end (the latter about double the former).