Confusion about tidal current

[Bill_Giles]

Why mess about trying to estimate tidal flow based on the time of high or low water. Simply look at the tidal stream atlas.

[MJH]

Originally Posted by mainemandean

I'm confused about something. At what point during the tide cycle is the current strongest?

Where we are, each ebb and flood takes about six hours. I have always thought that the maximum current is about at the 4-hour mark. Am I all wet, as it were?

I am reading conflicting things on this subject.

Where our boat is launched is a small bay; but it's long and skinny, and its entrance is a tiny funnel. The currents can be really daunting. This location is relatively new to us. I have assumed that if I wanted the least amount of current we should leave right at high, or right at low.

But despite what I've thought, even leaving the slip at those times, we've encountered very strong currents.

What's going on? Maybe what I've thought all along is just plain wrong?

Generally speaking, when is the max current flow? And in a bay as I described, which way, if any, does the pattern get skewed?

Good advice from GordMay. I would suggest you take some notes for each launch logging the posted high and low tides and what you experienced. Despite what the posted tides are the local geography will affect it somehow. Over a short time you will understand the tide better for your particular launch area.

[Dani-lu]

The strongest flow is in the 2nd, 3rd and 4th hour as the tide goes up and down. It starts out slow and builds to it’s fastest flow as it heads towards the 3 hour mark and then starts slowing down the same way it grew. See below diagram - I circled peak flow at top of diagram in red:

[blazing928]

Lots of advise about tide tables and rules or 12ths…

I also boat in Porrt Phillip Bay, Vic, and one thing I’ve learned is tide tables are set by maths stars moon and maybe a bit of voodoo.

I study the local tide tables and then note the areas I’m in and how they relate, so in essence i make my own local tide tables and current flows.

it takes awhile, but it will be the only accurate [ish] figures you will get.

[Grigory]

time of max current speed is depend mainly on local geografy.
If you stay at narrow place before some big basin (bay, estuary etc.) at high water moment current speed will be high.

for ex. Saltstraumen (Norway)


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