Slack Tide/Springer questions

Waterfish · 03-05-2004, 12:53 PM

Jesse, thanks for the explanation, I didn't realize slack tide only lasted for 15 minutes on either side of the tide change. By-the-way, I was planning to go fishing today but when I saw the forecast for heavy rain and especially 25 mph west wind, I decided to wait for a better day. Good luck on your trip Sunday!

Pitch Pocket · 03-05-2004, 02:06 PM

Not being picky, but just for your information, there is no such thing as a "slack tide". Time for a short tide and current lesson.

Tide is the vertical measurement of the height of the water. The time of a high or low tide, when the vertical motion stops, is called the stand.

Tidal current is the horizontal movement of water. Incoming is called the flood current and the motion away is called the ebb current. The time of little or no horizontal motion that happens before a reversal of direction is called slack water or minimum speed.

You can actually predict the duration and speed of slack water. It's a process using Bowditch tables that you have to learn if you take a piloting course.

Nobeltec's computer program called "Tides and Currents" presents those predictions in a graph form similar to a tide table. There you can get the predicted speed and timing of ebb and flood and the predicted duration of slack water. Slack water never happens at low tide in the Columbia upriver from Astoria, only high tide.

For instance, Saturday 3/6/04, low tide at St Helens is predicted to be at 12:50 pm and that is just shortly after the maximum ebb current. High tide is at 4:26 pm. The minimum flow before the next ebb or the closest thing to slack water you will get is predicted at 3:44 pm, and it's questionable whether your plugs will work between say 2:30 and 5 pm according to those predictions. The minimum flow is predicted to be 1.1 kt so it never really slows to a stop during that exchange. That changes as you get closer to the ocean, AND, all bets are off if they open Bonneville or there is a lot of run off.

In my experience, anything below 1 nm/hr is pretty slow, especially anchored near the shore in the best areas for plugging for salmon. If it slows to .5kt, it seems to stand still and you're probably swinging on your anchor.

It's best to be prepared for both trolling and anchoring when fishing during a high or incoming tide in the lower Columbia. You can go armed with predicted data, but in the end, if your sea anchor is hanging straight down, you better start trolling.

Blue Water 23 · 03-05-2004, 02:26 PM

That's my teacher explanation turned into a lawyer explanantion. :smile: Either way I am sure it helped

Pitch Pocket · 03-05-2004, 02:38 PM

Not a lawyers explanation, a pilots explanation. Sorry if it was too much information. :depressed:

legal_layover · 03-05-2004, 05:30 PM

In addition to first light, low tide is a great time for catching. Slack or no flow on the Columbia is very dependant on what they are doing at Bonnieville.

Waterfish · 03-05-2004, 09:11 PM

Pitch Pocket, That was a great explanation! Is the Nobletec Tides and Currents a free program (web site) or is there a subscribtion charge?

Waterfish · 03-05-2004, 11:03 PM

I understand how to use tide tables, although most of the time I use the graphic tide charts from either Tides.com or the Fishing Works web sites. From my understanding, slack tides are those periods right at the beginning of tide changes, is this correct? If high tide begins at 6:00 am for a given spot on the Columbia, how long does slack tide last? Does slack tide mean that the beginning of the incoming or outgoing tide, that the current of the river becomes neutral for a while? What is the significance of "high slack" and "low slack", and how should I use these times for springer fishing on the Columbia and Willamette rivers?

[ 03-05-2004, 12:06 PM: Message edited by: Waterfish ]

Blue Water 23 · 03-05-2004, 11:25 PM

Mike, You have to remember that those are predictions and aren't always right on, especially up the river a ways. Slack is usually 15 minutes before the tide to 15 minutes after. This holds true in the bay but in rivers it might just be less outgoing on an incoming and more outgoing on an outgoing. Last year from spring break, last week of March, on you could anchor and run kwickfish even on the incoming. If it is a steap incoming then you might have to troll. The spring runoff is coming.

I haven't noticed a constant part of the tide that fish bite best on but I have heard that the best is at first light, no matter what the tide, and the last two hours of the outgoing.

Silver Hilton · 03-06-2004, 09:33 AM

Pitch, thanks for the great tip and info.

Pitch Pocket · 03-06-2004, 02:49 PM

Thanks Waterman & Silver Hilton. I was hoping someone wanted to hear some technical details. :smile:

"Tides and Currents" is a program marketed by Nobeltec. Unfortunately, it costs about $100. Fortunately, it gets a workout by me. I use it nearly every day and never plan trips without consulting it.

I print out the tide and current charts on one page and use the back for my log of the day. Easy to track tide and current conditions for different events like maybe a fish! Here is what today's looks like.

(oops, not trying to advertise another board)