Editing Slack tide (section)

==Combined tidal stream and current==
In many locations, in addition to the tidal streams there is also a current causing the tidal stream in the one direction to be stronger than, and last for longer than the stream in the opposite direction six hours later. Variations in the strength of that current will also vary the time when the stream reverses, thus altering the time and duration of slack water. Variations in wind stress also directly affect the height of the tide, and the inverse relationship between the height of the tide and atmospheric pressure is well understood (1&nbsp;cm change in sea level for each 1 mb change in pressure) while the duration of slack water at a given location is inversely related to the height of the tide at that location.