how long is a lunar day
24h 50min
How long between 2 high waters
12h 25min
time between high and low tide
6h 12min
Spring tide moons are at…
Conjunction (new moon) or opposition (full moon)
Neap tide moons are at…
Quadrature
What effects tides
Barometric Pressure
Wind
Drying height
The height of a rock or shoal above Chart datum
Highest Astronomical tide (HAT)
Highest level a tide can get under normal circumstances
Lowest Astronomical tide (LAT)
Lowest level a tide can get under normal circumstances
Charted height
The hight of all overhead things, is measured from HAT. All singular structures (lighthouses) are measured from MHWS