Slack tide

[iztok]

I need bit of help understanding this in terms of when is the slack tide.

you can go to any number of online tools that would allow you to get times of high and low tides. How does one go from there to figure out period of slack tide?

I need to figure out when high slack tide period is on Cooper River in South Carolina. More specifically Old Rice Mill location.

So I picked up the days in question and used the following link:

http://www.mobilegeographics.com:81/locations/4408.html?y=2010&m=6&d=26

What data do I use to calculate slack tide? (Being new to the nautical terms etc. I am assuming that high slack tide is different than just high tide.)

Thanks!

 

[mike_s]

Slack tide is when the tide stops moving... it's the time between high tide and low tide. (typically the time that's indicated on the charts.)

often, in most locations, high slack tide is the better time to dive as it's just brought in clear fresh water from the ocean, instead of low slack tide which has just sucked out brackish bay water.

 

[Saudi-Diver]

Slack tide for us Scottish divers is a hour before high tide to an hour after or an hour before low tide to an hour after. Its catching the water when there is the least movement otherwise you fighting some huge currents! There are loads of web pages that help you plan your dives.

 

[iztok]

Thanks!

So given the info from above link:

Old Rice Mill, West Branch, Cooper River, South Carolina
33.0783° N, 79.9250° W

2010-06-26 5:26 AM EDT 0.33 feet Low Tide
2010-06-26 6:12 AM EDT Sunrise
2010-06-26 7:31 AM EDT Full Moon
2010-06-26 11:30 AM EDT 2.50 feet High Tide
2010-06-26 5:24 PM EDT -0.10 feet Low Tide
2010-06-26 8:32 PM EDT Sunset
2010-06-27 12:05 AM EDT 3.22 feet High Tide
2010-06-27 6:09 AM EDT 0.34 feet Low Tide
2010-06-27 6:12 AM EDT Sunrise
2010-06-27 12:14 PM EDT 2.50 feet High Tide
2010-06-27 6:06 PM EDT 0.09 feet Low Tide
2010-06-27 8:32 PM EDT Sunset


You would say high slack tide is between:

2010-06-26 11:30 AM EDT 2.50 feet High Tide
2010-06-26 5:24 PM EDT -0.10 feet Low Tide

But that is weird as it is quite a lot of time between 11:30a and 5:24p.

 

[iztok]

Slack tide for us Scottish divers is a hour before high tide to an hour after or an hour before low tide to an hour after. Its catching the water when there is the least movement otherwise you fighting some huge currents! There are loads of web pages that help you plan your dives.

Well I am looking for those more specifically for one for locations on Cooper River.

All I've seen have high and low tide times but from there to get specific high slack time is a guesstimate?

 

[SkimFisher]

Think of it as "peaks and valleys". [-]It's the period between the rise and fall.[/-] No, there's really nothing that's going to tell you WHEN slack tide is other than familiarity with the area and firsthand experience. There's no substitute for just going out and WATCHING the tide and how it moves in an area.

Edit: Let me rephrase that above:

Think of it like your toilets float switch. As the water rises the flow subsides until it's reached it's highest point (high tide). This would be the start of slack tide. Think of your toilets flushing action as the fall to Low Tide. Depending on the area you could have 30 mins to an hour between the two. Like I said before, this is where familiarity with the area comes into play. There's really no way to predict how much time you've got.

 

[otterdive]

I run in to people all the time who plan their dives for high slack tide, but they forget that there may be a period of time before, and after high tide, that, depending on the site, could be great diving. Some folks even arrive at dive sites at high tide according to the charts, and by the time they are all kitted up, it's too late to dive. Each dive site is different, and you should get LOADS of local advice if you are diving a site that is significantly affected by tidal action.

Also keep in mind that unless you are diving at the tide reporting station, there could be a great deal of difference in the tables, and the dive site.

 

[captain]

Slack tide or more correctly slack water generally occurs at or slightly after high or low tide. As long as the tide is rising or falling there will be either an in flowing current or an out flowing current.
High or low tide time predictions simply indicate the time the tide will be at it's highest or lowest point and not necessarily that water movement will cease or reverse at that time. Depending on location and hydrology current can continue for some time after high or low tide before slack water occurs.
At a particular location observation of the time slack water occurs is the only way to determine exactly when after high or low tide it occurs. Tide and current tables are based on the location and the relationship of the sun and the moon to the time of day. Weather is not factored in and can change the actual tides and currents.

Here is a site that may help you.

How to find slack - DIVE Skills & Thrills

 

[iztok]

Thanks captain!

Where can I find the "tidal diamond" data for particular location?

 

[captain]

Thanks captain!

Where can I find the "tidal diamond" data for particular location?

That is a UK site and I am not completely sure what he is referring to.
Tidal predictions are generally made for specific tide datum stations along the coast. Other locations have to be determined by adding or subtracting the number of hours or minutes from the nearest tide datum station as found in the tide and current tables published by NOAA here in the states.

Example http://wolfweb.unr.edu/homepage/edc/tides.html

NOAA site http://tidesandcurrents.noaa.gov/