How much current can there be?
Thought this might help a few to understand the volume of water moving through tidal rivers and lagoons:
If you average time between high and low tide to 6 hours then:
1/12th of the water moves in 1st hour
2/12ths in the second hour
3/12ths in the 3rd hour
3/12ths in the 4th hour
2/12ths in the 5th hour
1/12th in the 6th hour
This means that if the difference between high and low tide is 1.6m (tomorrow in Mooloolaba) then half the water (0.8m) will run into/out of the river mouth in a 2 hour period (during the 3rd and 4th hour after the slack tide)
This is obviously when the current is at its' strongest. The strength of the current will relate directly to the volume of water (size of river/lagoon) and how wide or deep the inlet is.
I hope the above info creates some understanding for somebody and helps them make an informed decision which could keep them out of trouble in the future or perhaps save a life.
Cheers
Erm.. half the water yes, but surely the cross sectional area of the conduit it flows through is relevant here, as is the shape, ie the depth or width will also matter, maybe even more. Volume through cross sectional area over time I guess. Oh how nerdy.
Now you get it Jim
This is why I said: "The strength of the current will relate directly to the volume of water (size of river/lagoon) and how wide or deep the inlet is."
Picture Port Phillip Bay in Melbourne where the bay is up to 120km long, the current can take a few hours after the tidal change to run through the relatively narrow opening and is normally around 6knots but can reach 9knots during king tides. Not that I would consider kiting between the heads but I guess it is good for illustration purposes.
