Standing wave off Felixstowe?

[Oldgeezer]

I've been across the deep water channel past Felixstowe many times but the first time I've encountered this.

Heading south - wind force 5 from the northwest, tide HW+2 springs. ( Monday 24th lunchtime) about 1/2 mile offshore.

I watched a tug boat heading out to renedzvous with a large container ship so I carried on sailing to cross the shipping lane approx 100yds behind him.
As I got closer I thought - that's a big bow wave for such a small tug, but it went for approx 300 yards along the edge of the deep water channel - about 6ft high. It looked like a wall.
No chance of going round so I ploughed through and got drenched. (so did my sausage roll!)

Anyone any explanation or encountered similar?

 

[Hydrozoan]

Where exactly were you? Not off Felixstowe town itself, evidently, as that does not fit with the 0.5m offshore.

If in the region near the Beach End / Rolling ground buoys, with a near-mid tide spring ebb and a strong-ish north-westerly wind, I would guess that the constriction and the bend (which also acts as a constriction) in the deep water channel might set up such a wave though I've not encountered anything as large in that area myself.

 

[rudolph_hart]

I've encoutered standing waves close in off Wadgate Ledge, by the small beacon. We'd come down from the Deben in a NE blow. That and the spring ebb made for a 'lively' run anyway (Reef 1 in Main, no headsail), but the waves off the beacon where the water suddenly deepens in the dredged channel made our (then) Dehler 34 seem rather small & frail. It was exhilarating, though.

 

[Oldgeezer]

Yes - I was between beach end / rolling ground. Should have said that earlier! I'd come down from the Deben where it was calm but wind getting up. Doing 6 knots well reefed by the time I got to 'the wave!'

 

[Hydrozoan]

Thanks for the additional information. To my mind, the bend – essentially 90 degrees – in the deep water channel there could act as a constriction, in addition to the physical narrowing of the channel, because flow would be intensified on the outside of the bend. On top of which, there may have been wave reflections – e.g. of previous wakes – off the shallower bank to the south of the bend which may have interacted with the outward flow and contributed to standing wave formation.

All very vague and unscientific, but it gives me a feeling that what you encountered is not inexplicable and, whatever the full explanation, your experience is surely a warning to expect the unexpected in such circumstances – so thanks for that!

 

[Boz]

I suppose it's not called "Rolling Ground" for nothing......

 

[Leighb]

And next door is the Pitching Ground. !!
Nearly always lumpy in that area with confused seas
I have never met such a wave but am not surprised.

 

[Hydrozoan]

I suppose it's not called "Rolling Ground" for nothing......

And next door is the Pitching Ground. !! ...

Indeed. I presume BTW that ‘Deane’ opposite Beach End / Rolling Ground is named for Sir Anthony Deane, 1638-1721 – Shipwright and Naval Architect, and Mayor of Harwich and MP along with Samuel Pepys http://www.harwichanddovercourt.co.uk/famous-people-local-characters/. He had a bumpy ride too at one point, being imprisoned in the Tower of London with Pepys on a charge of selling naval secrets!

 

[Leighb]

That's interesting, I always vaguely wondered who it was named after but was never sufficiently curious.

 

[Lucky Duck]

Often used to get some "interesting" moments by Languard Point when coming in against a spring ebb against a brisk wind with any South in it, usually on they way back from Woodbridge Tide Mill YH

 

[Biggles Wader]

Maybe you encountered the Orwell Bore

 

[Oldgeezer]

Certainly not George..

 

[phatcat1]

Maybe you encountered the Orwell Bore

A few of them at the Royal Harwich!

 

[WF36]

A few of them at the Royal Harwich!

Don't tell half a story!