How do you actually estimate...........

"He said (and I think this is a fairly accurate quote) "when people say that the waves in the Southern Ocean are about 120 feet, they are talking bollocks". He said the wave height was nothing like what people say"

If you check the possible wave height off the South African east coast, they are reported in pilots as being up to 30 metres in certain conditions & thats BIG!
 
I only know three sizes of waves:

Size 1, BIG: The one that reared up dead ahead, broke over the bow, rolled aft over the coachroof and swept me off the helm to pin me against the sternrail.

Size 2, BLOODY BIG: Like the one that reared up to double height, after we had successfully evaded a series of them for hours, and rolled us over as it broke, submerging the cockpit crew for some time before the boat righted.

Size 3: F...... HUGE! Like the series that we rode to round Butt of Lewis from the West, about a mile off, at night. The light was only visible when we lifted on a crest, and it was being monitored to verify progress. Just once, as we rose and the light re-appeared, it was obliterated by the blaze of lights of a trawler rising from what looked like the next-trough-but-one, and on a converging course! It disappeared as we both sank into our respective troughs, and we were on tenterhooks for the next rise to be able to assess risk of collision. But all we saw was the lighthouse.
We never saw the trawler again, and have long wondered where the hell it went! It can hardly have been an illusion shared by four people in the same seconds. We even wondered whether it had simply foundered, and listened for reports, but nothing!
Does anyone have an estimate of the masthead height of an ocean-going trawler?
 
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officially half the trough/crest height

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Me too but all that has changed with the arrival of less precise 'sailors' on the scene over the past 20 years.

I have been coming in over a Bar and watched an idiot taking a short cut inside the bar buoy to hear him on the radio telling everybody the waves are the size of a two-storey house (30 feetish). This when I am only 150 yards from him and can see the waves side on as they pick him up (4 metres if he's lucky).

Adlard Coles says everyone exaggerates unintentionally (mostly) and this is often up to a third too much.
 
Re: Strictly speaking

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it's from the trough to crest /2.

2m high waves (apparently 4m) are pretty commonplace.

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Do keep up - height is trough to crest (Twister Ken has posted a nice picture)
 
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Adlard Coles says everyone exaggerates unintentionally (mostly) and this is often up to a third too much.

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I think he's exaggerating /forums/images/graemlins/grin.gif
 
No, you don't get readings often enough, and the vertical accuracy is a 95% probability of being within 15 m; it is slightly worse than the horizontal accuracy. GPS readings are on about a 2 second cycle, so yopu'll also get interesting aliasing effects with the waves.

Paul
 
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