OCEAN RHYTHM

The "wavelike" white line shows the tidal variation for the given day. A white dot on the white line indicates the high or low tide respectively for the day in question... These two bands of predicted high and low tide values establish a footprint or tidal range for a given year. Predicted tides will always lie within this range. Note that such a footprint shows during which times of the day predominantly high-water or low-water will occur. For instance, "high water" is oriented around the 1st and 3rd quarter of the day, whilst low water is oriented around the 2nd and 4th quarter of the day... These ports are high-lighted on the selection page in blue and reflect tide data provided by the Hydrographic Office of the South African Navy. Primary ports have an official Chart Datum or reference altitude. All other (secondary) ports reflect tidal data which was synthesized by Ocean Rhythm. These ports do not have a chart datum (or reference) and the tide height shown is a range value..