slack tide vs tidal swing

[MuddyMike]

I hear people talk about slack tide lasting from 1/2 hour before/after to 2 hours before/after. I can't really find info on if the tidal swing plays into it though.

It seems like if the tide was going from 5.5 feet to -.5 feet, the slack tide would be less than if it were going from 3.5 feet to 1.2 feet.

Is that a correct assumption? If so, any theories on the time for slack vs swing? I'm trying to estimate slack duration for a tide reporting web page I'm working on.

Study tide graphs then you'll see slack tides can
last all day or just for a brief time period.

[Jimmyz123]

If I understand it correctly the slack tide you are talking about is the peak or the bottom of the tide swing in question. As Yani mentioned study the charts and it should tell you what type of lenght you are looking at. some tide peaks or bottoms may be longer than others.

Here's a link that will help you understand tide chart reading
http://www.coos-bay.net/understanding-tides.html

[Fiskadoro]

Originally Posted by MuddyMike

I hear people talk about slack tide lasting from 1/2 hour before/after to 2 hours before/after. I can't really find info on if the tidal swing plays into it though. It seems like if the tide was going from 5.5 feet to -.5 feet, the slack tide would be less than if it were going from 3.5 feet to 1.2 feet.

Slack tide actually refers to the relationship between tides and current.

To get how that relationship works you have to first realize how big tides are. Essentially gravitational forces from the sun and moon pull water around the planet....

.... we're talking billions and billions of gallons here, and that movement of water creates currents especially at narrows or straights harbor openings etc..

Tides move in cycles through the day...


The tides never really set still they are constantly moving forward to the next cycle but when they are at a high, or low there is less water movement and the current goes slack during the transition to the next tide.

Say you are at Mission Bay at the breakwall... during the periods of change there is a ton of current coming in or out. If the tide is rising it's coming in, if the tide is dropping the current is going out but at the points where the tide is at it's peak "High tide" and lowest point "Low tide" the current stops for a while because the water level outside the breakwall and in the harbor equalize to the same level. The current stops then or goes slack, and that is what is meant by "slack tide".

Slack tide, or the period of little or no current can last for hours or a relatively short period of time depending on how the moon and sun line up to effect the tides swing. It's extremely complicated, but generally times of large tides, or large tide swings, have shorter slack periods, and periods of smaller tides have longer periods of slack tide where there is little or no current.

As to fishing...well... fish are all about energy exerted to reward gained in food. So fish either use current to their advantage or the just avoid it.

In the past I've found that halibut will sometimes bury themselves in the sand then ambush prey that washes to them pushed by the current of the tides, in contrast the best bites on Seabass for me have always been on slack tides, mostly high tides, but like with all fishing it varies to conditions and the key is to figure out what the pattern is where your fishing and then use it to your advantage.

For instance say the seabass have been biting at one place off the kelp during the slack tide created by a 6.5ft high tide in the evening between 11and 12pm. Well if you look at the tide chart for the day and you see a big high tide between 10pm and 1am, it's probably a good time to paddle to that place and soak some baits during that particular high tide, and the slack tide that is created when it tops out.

It's still fishing and nothing is a sure thing, but if they have bit on those conditions before, they may well bite on them again.

People often ask me like whats the best tide to fish on, but there is no best tide. It's all about knowing how fish are going to react to a certain tide pattern in a certain location at any given time, and the only way you can learn that is by time on the water and learning the fishes feeding patterns in relation to the tide patterns, currents and swings.

Understanding the basics involved with tide patterns is a big plus, but learning to apply those basic ideas to fish feeding patterns and real on the water situations, and then being able to predict fish behavior as a result, that's the holy grail of fishing with the tides in mind.

Jim

[Regor]

.... shoot ! I just wanted to fish, now I gotta go get a degree in Oceanography and Meteorology

[MuddyMike]

great info guys, thanks. i think i have enough info to calculate a good estimation on the slack time around the high and low based on the previous and upcoming swing.

maybe this will be a futile exercise, and maybe it will be useful info. i'll post a link when i'm done and you call can be the judge

it's a lot of fun to think about while i can't get out there and fish anyhow.

[Vikingj]

Thanks, Professor Jim. Seriously, that's the best explanation I have ever heard and I have a degree in Marine Bio.
Wayne

[old_rookie]

Originally Posted by Regor

.... shoot ! I just wanted to fish, now I gotta go get a degree in Oceanography and Meteorology

Father to wife - "Sorry, can't go see the child in her talent show that night, slack tide."

a few days later... new forum topic: "How do you fix multiple holes in a kayak"

[mtnbykr2]

Originally Posted by old_rookie

Father to wife - "Sorry, can't go see the child in her talent show that night, slack tide."

a few days later... new forum topic: "How do you fix multiple holes in a kayak"

LMAO...

[bubblehide]

Originally Posted by Vikingj

Thanks, Professor Jim. ...Wayne

oops, words out Jim, now everyone knows you true profession.

[Fiskadoro]

Originally Posted by Vikingj

Thanks, Professor Jim. Seriously, that's the best explanation I have ever heard and I have a degree in Marine Bio.
Wayne

Wow Thanks! That is quite the compliment

[mtnbykr2]

Originally Posted by bubblehide

oops, words out Jim, now everyone knows you true profession.

great now I gotta go home and study/memorize Jim's lesson tonight, thanks Jim