Tide words
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  1. Tide = the vertical RISE and FALL of the ocean water.

  2. Tidal range = diffenrence between successive HIGH and LOW tides

  3. Spring tides occur when it is NEW moon and FULL moon.   Spring tides have a BIG tidal range.
    In Darwin that can be up to 8 metres .

  4. Neap tides occur when it is QUARTER moon and THREE QUARTER moon.   Neap tides have a SMALL tidal range.
    In Darwin that can be as small as 1 metre.

  5. Semi-diurnal : two tides a day (as in Darwin)

  6. Diurnal : one tide a day


  7. Tidal stream = horizontal water flow that results from tides.

  8. Incoming tide ("flow") = when the water is rising.

  9. Outgoing tide ("ebb") = when the water is falling.

  10. When the tidal flow and wind are in the same direction you have a smooth ride in the boat.

  11. When the tidal flow and wind are the oppositie direction you have a bumpy ride in the boat.   So-called Wind-over-Tide.


  12. To allow for the tides put out twice as much anchor rope as the depth of water plus expected tidal range combined.
    So when the water is 3 metres deep and the tidal range is 6 metres, put out at least (6 + 3) x 2 = 18 meters of anchor rope. This ensures that the angle between seabed and anchor rope ≤ 30° at high tide.

  13. When cruising with the tidal flow, travel faster than the tial flow speed, otherwise you lose the ability of steering the boat.