Tidal currents
Can understand tidal currents by envisioning tide as one of three types of wave
Progressive wave tide - where coast is too irregular to give pronounced reflection, so no standing wave
- High tide = wave crest; low tide = wave trough
- Flood current coincides with high tide; ebb current coincides with low tide
Standing wave tide - in confined rectangular basin
- Slack water coincides with high or low water level
- Flood and ebb currents coincide with mean water level
Kelvin wave tide - azimuth & magnitude of currents may vary