Help with Current Predictions

[Rick Inman]

I just bought the book, Current Predictions for Northwest Shore Dives, and I'm not sure of one thing. My question is about when there are 3 E's (ebb) in a row. The text of the book says,
On days when there is only one flood instead of two, the preceding ebb current slows as it approaches slack (speed approaches zero), and the direction becomes unpredictable.
When there are three consecutive “E”s, the middle entry represents a similar situation, but the direction and speed are more predictable. In theory, flood currents could also occur in this pattern.

Here is an example:

27_______0358 1.5 E
Th_______0858 0.9 E
_________1513 2.0 E
__2027__2206 1.0 F

Obviously slack time is 20:27, but except for then, when would be the best time to dive on this day, and why?

 

[MXGratefulDiver]

Rick ... looking at the tide and current charts for the 27th, I believe the numbers you cite above are not periods of slack, but rather periods of maximum flow ... and the relative speed of flow.

To answer your question ... it appears to me that there is a very small tidal exchange from early morning till about 8 AM, at which point you're going to get a modest (4-foot) ebb exchange till roughly 3 PM ... followed by a 5-foot flood till around 11 PM.

Best times to dive? From the above information at the site, I'd say anytime before noon ... due to the very small exchange ... and again between about 3 to 4 PM, around SBF.

The three ebb points shown are the result of the fact that the tides on that day ebb ... stay pretty flat for a couple hours ... then ebb again. All that happens really early ... from about 3:30 AM till around 8 AM or so (I'm looking at charts for Port Angeles and Neah Bay and doing some interpolation here).

Hope that helps ... but from the looks of things you've picked a very good day (tides wise) for Salt Creek. Let's hope the weather and wind cooperate.

... Bob (Grateful Diver)

 

[Rick Inman]

Rick ... looking at the tide and current charts for the 27th, I believe the numbers you cite above are not periods of slack, but rather periods of maximum flow ... and the relative speed of flow.

To answer your question ... it appears to me that there is a very small tidal exchange from early morning till about 8 AM, at which point you're going to get a modest (4-foot) ebb exchange till roughly 3 PM ... followed by a 5-foot flood till around 11 PM.

Best times to dive? From the above information at the site, I'd say anytime before noon ... due to the very small exchange ... and again between about 3 to 4 PM, around SBF.

The three ebb points shown are the result of the fact that the tides on that day ebb ... stay pretty flat for a couple hours ... then ebb again. All that happens really early ... from about 3:30 AM till around 8 AM or so (I'm looking at charts for Port Angeles and Neah Bay and doing some interpolation here).

Hope that helps ... but from the looks of things you've picked a very good day (tides wise) for Salt Creek. Let's hope the weather and wind cooperate.

... Bob (Grateful Diver)

Thanks, Bob!!!!