tidal rivers and timings

[oliverm]

I want to take my kayak out on a quiet stretch of our local river,the Arun.

We're about 4 hours delay up from the mouth of the river. So if high tide is at 8 at the mouth then we get high tide at 12.

So is it fair to say that, if going for a few hours up-stream, to make the most of the tide I should leave a few hours before our high tide, so a few hours after high tide at the mouth but a few hours before high tide locally?

Does that make sense?

Olly

[stormkayaker]

Have a look here:

http://www.ukriversguidebook.co.uk/rive ... arun-tidal

[oliverm]

Thabks for the post but I was hoping more for confirmation of whether my workings were roughly correct.

Lets forget its the Arun, or any other river, would those kind of timings be right?

Olly

[Chris Bolton]

I suggest you aim to reach the upstream point of your trip maybe 30min before high tide, at that point. That gives you time for a break, or for your timing to be out, and you can go back down with the tide. The time you need to start depends on the speed of the upstream tidal flow (and it varies between springs and neaps), the amount of fresh water flowing down the river, the time of high tide at where you're heading, how fast you paddle, the wind direction and strength...etc. So, yes, your plan is correct, but it will probably take a bit of trial and error (ie, several trips) to work out the value of all those "few hours".

On the way back down, you'll probably find that the tide goes out more slowly than it came in, so when you get back to your launch point the level will be higher than when you set off. So pick a start/finish spot that works at various water levels.

Chris

[jamesl2play]

I am marooned in the house today so here are my thoughts.

It is difficult to generalise across all rivers they have different characteristics. Some things to consider first are:

Does the estuary dry out at LW you do not want to be stuck on a sand bank on the way back. If it does not dry how much is the tide an issue.
Is the tide Springs or Neaps bearing in mind a Neap flow is generally taken to be half that of a Spring tide and will not reach so far up the river.
The amount of freshwater flow down the river.
Direction of the wind, a strong wind will assist or restrain both the water and the paddler.
High or low pressure could also have an effect as to how far the tide will travel up the river.

Take account of the 50/90% rule - see Francos book.
There will be slack water one hour either side of high and low water. If you paddle upstream do not expect to turn around at HW slack and get tidal assistance back down straight away.
One hour after HW the tide will flow at 50%
Two hours after HW the tide will flow at 90%
Three hours after HW the tide will flow at 100% and then start to slow at the same rate until slack LW.

From what I have just read relating to the Arun aim to start paddling back down the river (from Pulborough) just over three hours after HW Shoreham (today approx 11.30 UTC) You will have to make your own judgement as to the timings of the trip taking account the potential effect of the above factors and how fast you normally paddle.

Hope that helps.

Jim

ps just seen CB beat me to it but I will post anyway

[GrahamKing]

Just one small caveat about the 50-90 rule: it really applies to coastal areas (and even then, not everywhere). On a river the 50-90 rule might apply near the mouth of the estuary, but the higher up the river you go, the more the horizontal movement of water will be dominated by the natural fresh-water flow of the river. The water will start flowing towards the sea some time before high water, and will continue to do so until some time after low water. The higher up the river you go, the greater these time differences will be, until eventually you find yourself on an inland river flowing always towards the sea.

[nickcrowhurst]

Olly, on your way upstream I'd be grateful if you would go a little upstream of Pulborough to the lovely Stopham Bridge, and its even lovelier pub: http://www.westsussex.info/stopham.shtml
Fifty three years ago (1959) I was a 12 year old hooligan on a small motor boat at Stopham Bridge. As we drew to a halt outside the pub, I threw the anchor overboard with great enthusiasm, but without ensuring that the requisite cordage was attached to it.
The owner of the vessel is now beyond mollification (RIP), but the recovery of the anchor would help heal an old self-inflicted dent in my pride. Look 20 yards below the bridge on the north side. I tried many times to locate it. Perhaps you might have more luck.
Reward offered, of course. (Where are those Smilies when you need them most.............?)
Nick.

[oliverm]

Baja I live down the road from there so that, or the coffee shop in pulborough,is my put in.

I'll look out for it.

Olly

[Mutsurfx]

We're about 4 hours delay up from the mouth of the river. So if high tide is at 8 at the mouth then we get high tide at 12.

So is it fair to say that, if going for a few hours up-stream, to make the most of the tide I should leave a few hours before our high tide, so a few hours after high tide at the mouth but a few hours before high tide locally?

Hi Olly,

Yeah, that's your best bet. As previously mentioned by others it's a bit hit and miss thanks to all the contributing factors, but we used to go with that rule of thumb, when launching from Pulborough. The tide does not reach much beyond Stopham and in any case a mile or so beyond we found the river to be overgrown with trees and impassable. I imagine the club cut their way through on their trips, but like you, my free from kids time does not coincide with club timings.

Still, it's a nice paddle. If you are interested, our trips will be in the blog link below...

http://wavemonkeys.wordpress.com/2009/0 ... -the-arun/

Cheers,

-Mut.