Wind and Tide

[morgandlm]

I would be interested in other folks experience of wind-over-tide and wind-with-tide. Last Thursday I went from Bradwell to Pyefleet Creek on a falling (East going) tide into the fresh Easterly wind (F4-5). The smoothest water was in the shallow water to the south of Mersea and north of the deeper Blackwater channel. This was what I had expected with wind-over-tide and to keep my wife a bit happier, I stayed out of the main channel. She still wasn't very happy!

Returning to Bradwell on Friday in a much stronger F5-6+ Easterly I was running with the rising (west going tide), i.e. wind-with-tide. The water was much flatter and easier to sail through in the deep water of the main channel. The shallower water closer to Mersea was much more lumped up and unpredictable. I had not expected this so have learned something. It was a fantastic sail back to Bradwell, although it did involve a bit of adrenaline! What was happening here? Was this a normal outcome or just a bit of a freak because of the big spring flood and a lot of wind that simply produced flattish water where it was deep?

The other lesson, by the way, was not to be out with my wife in an F5/F6+ blow. I enjoyed it though! I was glad not to have been out in The Wallet which had been the original plan.

David Morgan

 

[oldgit]

While nipping along in the Princes in a classic stiff wind over spring tide situation, the white tops on the waves in the inshore route are very noticable indeed.

 

[johnalison]

Wind-with-tide (which to me is also wind-over-tide, but that's another story) will flatten the water as the opposite to wind against tide. You could think of it as the water with less or no tide experiencing more wind, though I think the hydrodynamics are probably more complex.

The water off Bradwell can get very rough in a westerly blow on the flood or vice versa. I remember sailing in company with our friends' then Sadler 32 and seeing its hull disappear in a trough just there. There is another tidal stream effect off the Stone, which we used to call the Stone blow, though without such high waves.

 

[peter.m]

I was on the crouch thursday. With the wind directly into the esturary and against the spring tide, it was unusualy bouncy. The last couple of miles between burnham and the roach definatly required an extra hand for the boat. The sea died again, once the corner into the roach and towards paglesham, was turned.

 

[Medway Mudlark]

Returned from Burnham to the Medway last Thursday, found the bottom end of the Crouch unusually 'swelly' but carried on out. Fell down 2 or 3 holes but once round the Whittaker, made the call and decided to carry on as we had the waves on the stern, which made for quite an exhilarating ride back, something like standing on a 28 ft surfboard powered by a largish engine at 16 knots. I am so glad I replaced the impeller the day before, as on the way over noticed she was running a bit warm. We have owned this particular boat (Fjord 815 sse) for 5 years, and when we posted after buying her, someone replied 'it will do you well'. They were bang on! Having run from Maplin Edge to Folly Point on the Medway at 16 knots due to the normal end of season fouling. The only casualty being an apple that fell off the cabin table. Have yet to tot up the diesel bill.

 

[guernseyman]

This subject was aired thoroughly here a few years ago, with many trying to explain the effect of the wind on the waves. To no avail. The name 'wind over tide' is a complete misnomer. The real effect is a wave train against current.

The role of wind is just to create the wave train, and it need not be blowing in the same direction, or at all, when the effect is observed.

When a wave train impinges on a counter-flowing current, the wave length is shortened and the waves become steeper, and thus less easy for a boat.

 

[johnalison]

and thus less easy for a boat.

"Less easy". I like that.