tidal streams near Watchet

zlod

zlod

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I've been having a "discussion" with a mate who is sailing with me this weekend: hopefully to Watchet and we are having difficulty resolving the answer to the following question...

The Bristol Channel tidal stream atlas (NP258) shows a weaker tide (than in the central Britstol Channel) close to Watchet on the ebb (small tidal arrow). On the flood there is no tidal stream arrow close to Watchet. One point of view states that there is hence no tidal stream close inshore at Watchet on the flood. The other point of view states that the tidal stream is similar to that in the central Bristol Channel. Which view is more correct?

We're hoping to sail from Portishead to Watchet (if there is some wind) and are trying to work out what sailing we do once we get to the Watchet area: it would be embarassing to sail past at low water (after the ebb) and then not be able to make it in at high water (on the flood).
 
But if you sail past Watchet with the ebb from Portishead, you'll be coming back with the flood, will you not?

We anchored in Blue Anchor close in a few weeks back, spring tides, and there was certainly a strong flow. IIRC, our log was reading over 3 knots when we were at anchor.

btw, I've only been there once, I'm sure the more experienced will answer as well.
 
Alcyone> Yes, we should be coming back with the flood. If we assume a strong flood tide close to Watchet then we could get back to Watchet too soon (before high water) and have to doodle around there. If we assume a weak tidal stream then we might not get back to Watchet in time. Alternatively if we don't quite make Watchet on the ebb for some reason, it would be good to know whether the strategy should be to go inshore or stay offshore.

I'd generally like to know how I should be interpreting NP258. I don't know how accurate it is for local conditions. I was very surprised by the strength of the tidal stream around Rhoose Point a couple of weekends ago and felt pretty helpless not knowing whether I should be trying to go inshore to fight the tide or to go offshore. Inshore didn't seem like a very good plan! I'd like to avoid this sort of situation going to / from Watchet.
 
OK, I'm with you there and have posted the same questions myself. The atlas shows strengths of 4.6 knots springs off Barry, and 3 knots off watchet. I can't speak for Barry, but from what my very limited experience has taught me, 4.6 knots does not seem outrageous in the channel.

I think the 3 knots out in the channel does not apply close in. The watchet pilotage instructions suggest 4-5 knots springs.

http://www.watchet-harbour-marina.com/whm_pilotage.htm

And I think it was nearer that when we anchored the other week.

I've very interested in this myself, as well as any useful 'back eddies' that may occur. They are often useful.

I'm far too inexperienced to offer more advice at this stage, however. I'm sure one of the others will be along soon.
 
Hello Zlod As Alcyone says there is strong tide close to the breakwaters at Watchet . This weekend its small tides anyway so not such a problem.

Coming from Portishead ideally you would leave at HW and carry the ebb all the way anchor in blue anchor bay then go back up to arrive at Watchet when the gates open.

With the neap tides this weekend if you left a bit late so the tide turned against you for an hour near Watchet you would still be able to sail/motor against it.
 
As an addition, I am told that close in, there is a strong tide going West on the flood.

Does anybody know about this
 
Tangomoon> you're talking about an eddy then? Or am I misunderstanding this?

***

I feel that there is much greater intricacy to the tides in the Bristol Channel than is shown in NP258 or the tidal diamonds on the local charts. NP258 basically says that the tides go up the Bristol Channel at 2-4 knots on the flood and down the Bristol Channel at 2-4 knots on the ebb. There isn't much detail beyond that. Maybe there's more information in the Admiralty Sailing Directions (there isn't in the commercial pilot books I've seen). I guess I'll find out all the intricacies with experience....
 
Yup this is correct... tides go up the Bristol Channel at 2-4 knots on the flood and down the Bristol Channel at 2-4 knots on the ebb. Thats about the size of it... you might as well get used to it... the only way you can possibly buck the tide is by getting right in shore, and I do mean well into soundings, which I would'nt contemplate now unless racing perhaps, another way is to get in the back eddy behind a headland such as Foreland or Hurlstone or some such, even then one has to eventually depart into the stream and more often that not the advantage gained is dissapated by the increased velosity of the stream created by the headland, do take full advantage of a following tide by departing at least two hours before the next fair tide, when the stream is decreasing in strength and don't forget you get an extra minute on average of fair tide for every mile travelled West to East and loose a minute when traveling from East to West, this is because the tide turns earlier further down channel, ie H.W. at Ilfracombe occurs aprox an hour earlier than say Avonmouth... so there... /forums/images/graemlins/confused.gif
 
Planning on going over to Watchet myself tomorrow, due to the neaps the tidal gate at Watchet is likely to close earlier due the current high pressure so dont rely on the published opening and closing times if your cutting it fine on time of arrival. Tomorrows afternoons published final lock in is around 6.05 pm however the harbourmaster advised that it is likely to be nearer to 5pm.

Im pleased to say that with 20knots cruising tidal streams do seem boring! /forums/images/graemlins/laugh.gif
 
Yeah, I think I'll have to get used to the tidal streams. NP258 doesn't seem like such a good investment now!

Given that there isn't going to be much wind this weekend, there doesn't seem to be that much point motoring over to Watchet (or more to the point, motoring back - there seems less wind on Sunday). The plan now is to just go down from Portishead towards the Holm Islands on the ebb and then back towards Bristol on the flood (i.e. a day sail on the Saturday).
 
Not sure about describing it as an eddy thought it must be!

Chap I was talking to last year said a chap /forums/images/graemlins/laugh.gif

in Watchet told him that if he kept close in, really close in, coming E after leaving Watchet there was a pretty strong tidal stream to carry him E in the last 2/3 hours before HW.

Chap said there was BUT you had to be close 50yds.

We came up with the tide a couple of weeks ago and were inside 100 yds close to cliffsfrom Watermouth up to Porlock but didn't experience tide against us.

We noticed that at Porlock, the tide goes from W to E all the time unless it turned twice while we were asleep!

Hoping to hear from anybody who has done the contrary tidal flow close in apart from Porlock
 
I think most of the Bays will produce either an eddy or at least a much weakened tide.

The most obvious one i know is beween Portishead and Portbury dock If you motor in towards the muddy foreshore it almost spins the boat arouind with 4 knots of east going on the stern and two knots west going on the bow.

Off the entrance to Barry the tide is almost allways setting you from East to West as you approach the Breakwaters.

Personally I wouldnt take a chance going tight inshore to a rocky foreshore such as off Watchet just to get a little lift.The consequences of getting it wrong would be severe.

Watchetforeshore.jpg


Coming up channel from the Nash towards Barry you can escape the worst of the tide by getting close inshore.To avoid Castle Rock ensure you can see Sully Island open of the headlands,if you can you cant hit it..If Sully Island is hidden behind the headlands then you can hit the Rock /forums/images/graemlins/blush.gif

In Weston Bay the tide runs South all the time ie from Knightstone towards Brean Down so if the flood tide pushes you too far up once you get into the Bay it will bring you back down towards Brean Down again.
 
Agree - rocks peter out either side of Watchet though - from memory?

I always keep a weather eye on this kind of too good to be true info but the chap seemed sincere at having done it
 
you have got the eddies all over the bristol channel you have the one off penarth, you have them in swansea bay, you certainly got them off st gowans to linney head .you normally find its the 2 hrs before and after the extremities off the tide
local knowledge is best. todays world of litigation every body hedges their bets i think thats why you dont see the eddies in books or tidal atlas its about asking locally and experience.
 
It was local knowledge - the chap I spoke to said the current existed in close - we didn't find it before Porlock so maybe it's just between Watchet and there.

There is the same thing rounding Lands End, which gives you something like 9 or so hours of fair tide
 
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