Tidal Streams

Athene V30

Athene V30

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Yesterday I left Ramsgate a couple of hours after HW to take the N'ly stream up to Foulgers Gat, cross the Sunk at LW and take the flood up to B'sea. Normal plan for me, done it before BUT inpractice I really didn't experience any set to N or NE as the tidal stream chart would suggest.

Thinking about it - well sailing singlehanded the crew (nearly) always agrees with me - I have convinced myself that as we have had NEly winds for what seems forever the surface water is moving SW and any tidal stream is below the surface and not any use.

Am I being stupid? Has anyone else experience it?
 
I think its worth taking all sail off, or at least power down to see what direction you float in. that would give a fairly good clue.
Try this in the Edinburgh Channel and you will get spurious results. /forums/images/graemlins/grin.gif
 
Wind borne current certainly has an effect. Some years ago after continuous south westerlies we arrived hours earlier than planned, from Ushant to the Needles.
 
Whatever the tide should be, it always seems wrong from N Foreland to Foulger's Gap. You need to take Charles Stock as pilot.
 
You've prompted me to get out my tables. I assume you mean HW Ramsgate, in which case averaging 5 kts, your passage up past North Foreland would be a bit 'middle of the road' in terms of tide assistance taking you 61 minutes to get to a waypoint just clear of the North Foreland. The 'quickest' possible (in the sense that you get max tide assistance) would be 45 minutes departing HW Ramsgate. From the North Foreland to the Outer Tongue (ish), you should get good assistance from the north going tide. (it would take you 67 minutes at 5kts - best would be 65 minutes if you had headed off from the North Foreland around HW Ramsgate so that's ok - worst would be 95 minutes 5 hours after HW Ramsgate). From the Outer Tongue to the entrance to Foulger's Gat would (still at a 5kt average) take 55 minutes - the best possible with the worst case being 77 minutes being there nearly 5 hours later. That's using the neap table.

So there's absolutely nothing wrong with the plan if you planned a 5kt average. I am sure that there is a lot in the idea that there is surface effect from the wind. There is also the point that if you failed to keep to a 5kt average, for example up to the North Foreland, then you will tend to lose beneficial tide assistance.

I am intrigued though that you don't do Fisherman's and the Sunk Beacon which knocks about 2.75nm off the journey.
 
Had planned to leave at 7am, 2hrs before HW Dover but in end I left at 0630 on Tues 27th. Planned on 5 knots.

I was using Foulgers and crossed at 51 41N 1 24E as I was expecting it to be lumpier than it was and there is more water there.

I do use Sunk (16) and Fisherman's too but have found there is a lump growing off the top of middle sunk
 
I agree with that shallow bit over the Middle Sunk although I haven't been there this year yet. Had 4 ft under my keel there last year - on a nice flat day!

Forgive me being anorakish, but my estimate is that keeping up a 5 kt average, I would have expected you to get to the Colne Bar around 14.00. That's using passage planning prediction tables for the route you used excepting that there is probably about a mile extra as 'my' waypoint on the Sunk was 0.62nm NE from yours. All that is theory of course since its based on tidal estimates.

Looking at the 5kt tables, that looks about the perfect start time. Some could argue that you could have gained more tide from the Sunk Sand to the Spitway (about 20 minutes) if you had run a little later but that would be at the expense of the loss of about the same time from North Foreland. It would be intersting (well for me anyway) to know what time you approximately made the Colne Bar?
 
Thanks, I would be interested. I had allowed half an hour for extrication from Ramsgate marina to outside but that would seem to suggest that you got the tide you should have done. Mind you if there is a surface effect, what you lost to Foulger's should have been picked up from the Sunk to Spitway.
 
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