Cherbourg - one person's true story

Re: Weather forecasts

I'm not doubting the definition - but wondering what wave height we actually experienced on Sunday - my estimate would have been a significant wave height in the 1.5-2.5m range (individual waves could of course be up to twice that height)

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Re: Weather forecasts

The fact that there isn't a consensus isn't surprising. It's notoriously difficult to make wave height estimates at sea, which is why the Beaufort scale is made up of a number of observations to judge the wind force (wave height being one of them).

You probably know that it was designed around the 13 'states' that Beaufort observed a man-o-war to be in in terms of sail plan, from full rig to bare poles. The admiralty, having adopted his scale some years later, had coastal observers looking out to sea to judge the conditions and report back.

I spent some years as a professional navigator and we had to make hourly estimates of wave heights for the log. Occasionally we would have a heave meter on board which at least helped to estimate the swell. Even so, I reckon it's very difficult to judge and the range reported in this thread is indicative of the problem.

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Re: Weather forecasts

Well, all I can say is that they were bigger then me.. Funny how your boat gets smaller when the waves get bigger!!

Ian

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Re: Weather forecasts

One must remember that true wave height is half the vertical distance between the trough and the crest - according to Adlard Coles. Most people seem to judge the height of a wave looking up from the bottom of the trough.

John

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Re: Weather forecasts

Which, when you are at the bottom of the trough John, seems to be a good idea!

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Re: Weather forecasts

I'm really puzzled... what time were you guys midchannel? We left the Needles about 15:00 Thursday, and were entering the Alderney race by 01:00 Friday. Once the tide turned to the west (late PM thursday) the seas werent that rough and we only saw occaional gust above 25 knots (we only got about two waves splashing on deck). On entering the race we had wind and tide against each other (he says mindful of the wind over tide discussions) as we slid into the top . It was then genuinely rough. Once the tidfe was running S (rather than E around Jobourg) at flattened out - but the top mile or two was very rough (waves about 6/8 feet over deck, so about 2 - 3 metres), but period was longish. AWS was up to 30 knots, helped by the weather going tide, but never more. By 04:00 we had shaken out reefs, and changed up to the big jib, and wind was down to the mid teens.

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Wave height

Must say both on the way out on Friday morning and on the way back, I didn't feel the waves were especailly big - never had that buried-in-a-trough-and-no-horizon feeling. Buit they were distinctly irregular with no very clear pattern which made steering through them a bit of a problem. And quite a few had breaking crests. On Passing Trade we did fall into a couple of holes on the way back. One jumped Tescotrev from the windward side of the cockpit to the leeward while Parahandy went base over apex down below. The other dumped many gallons of h2o in the general vicinty of the engine control panel, and set off a warning buzzer, which we reckoned was due to water ingress.

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Re: Weather forecasts

Qsiv, on the way out the worst weather seemed to be experienced by those who left east-about the IOW in the first half of Friday. So we were about 12 hours behind you and further east.

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Re: Weather forecasts

The wind over tide effect seems to be more acute the further up channel you go, and their was likely to be some acceleration of the wind as the land squeezes the wind. Even so it seems to have been radically worse 12 hours later and 30 miles east.. or there again maybe it wasnt just my lunch fighting back and I was genuinely feeling a bit 'ick!

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Re: Weather forecasts

We crossed during the day on Friday - so mid channel midday on Friday. We all experienced F6 winds on the way across. This tallies with the weather reports from coastal stations at 0500 that morning that gave F7 from Sandettie and Channel Lightvessel Automatic.

I left Portsmouth at 0645 under full main and #1 but soon put one reef in the main. As we went south from Bembridge the wind appeared to strengthen, and the seas increases, and we needed 3 or 4 rolls in the genoa to keep the boat on her feet. Whether that apparent increase was the wind genuinely getting stronger, or whether it was coming out of the shelter of the IoW I'm not sure, but I would think mainly the former.

After that the wind was pretty steady in both strength and duration for the entire trip. People who set out later that evening experienced equally strong or stronger winds to start with, but then they dropped off

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Re: The engine vibration.....

If there was a dodgy mount or two before, probably from the round-the-world trip of Asterie's previous owner, I'd have expected them to be noticed by the surveyor.

Maybe worth a closer look?

Hope she gets sorted soon, mate.

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Re: Weather forecasts

Thanks for the detail - it looks like it was genuinely rougher and fresher than I had felt. We just didnt seem fully powered up with one reef in the main. Maybe it was that the sailmakers had re rove the #1 reef pennant too far aft on the boom, and the sail was too full, and short of leech tension. I couldnt face the prospect of trying to sort it out at sea as the boom is 7 feet above the side decks, and the motion was sufficiently energetic to make me reticent about climbing out along the boom to sort it out as darkness fell. The second reef would have been fine had we needed it so there wasnt a safety issue. We did change down from jib to staysail to keep things balanced.

When we left on Thursday afternoon the wind was so light and the forecast for so little wind that we rummaged through the sail locker, extracting spinnaker sheets, barber haulers and strops in expectation of needing to rig the Code 0, to keep us going through the night. How wrong can forecasts be...

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In my Garden

It was blowing around F3 and it played havoc with my attempts to clear up all the leaves and get them into the MkVII composter and Dear Heart wasn't best pleased when she got back from her sister's (the one with the nice bottom) and found that I hadn't really finished.
So don't just think that you boys were the only ones experiencing stormy waters

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Claymore
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Re:Wave height

One must remember that true wave height is half the vertical distance between the trough and the crest

surely that would be level and therefore no height at all. Will not every thing above the halfway point be true height........../forums/images/icons/crazy.gif

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Re: The engine vibration.....

Thanks Nick,
They hauled her out this morning and the stern tube and area around it has survived.
I'll not find out how many mounts were shot before next week -

Ian



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Re: Cherbourg - one person\'s true story

I've just returned home for the first time since Ken's post, so this is my first opportunity to respond.

Firstly, my sincere thanks to Ken for the trip on Indigo - the decision to go back was one that none of us wanted to make, knowing we would probably get some stick for not making it to Cherbourg. However, the mark of a good skipper is to make the sensible choice, and when I ventured "is anybody actually enjoying this?", and Trevor's request of "Is there anywhere else we can go?" ("NO" was Kens reply) it was put to the vote - we unanimously agreed Portsmouth was the sensible choice. The biggest problem was not the wind, or the sea state (though this was pretty lively and set to build further as the tide turned), but the eta the Garmin was giving us - another 14 hours!!. The bloody IOW seemed to stay more or less in the same position during the last couple of hours!

At no time did I (or I believe Trevor) feel anything but safe - uncomfortable perhaps, with the boat being pushed around by the seas, and a few bruises to show for it, but at all times utterly safe. Indigo is a superb, very seaworthy boat, and would have looked after us in anything the Channel could have thrown up (Ken's not a bad skipper either!) The main reason, as I saw it, for our turning back was the direction of the wind, which was backing Southerly, not veering Northwesterly as forecast, thus forcing us into a situation where tacking seemed quite likely, and extending the 02.00 eta even further.

As Ken says, the Mrs Nicho travel service could not come up with ideal fery times, and the call from Jimi was perfect timing, as we were just coming through he Forts at the time. Following my earlier visit to Mme La plume's, I decided that as the rash was getting worse every day, I ought to bring my doctor's appointment foreward, so went home and into quarantine!.

Thursday next (23rd), I'm off to Gibralter to help take a Jeanneau 452 to Gran Canaria, via Casablanca, Lanzarote and Tenerife (it's doing the ARC), a trip of some 800 miles. I'va had to own up to Mrs Nicho that two of the crew are ladies, but she reckons, no one in their right minds would come anywhere near the area of La Plume skin irritation.

I'll post chapter and verse when (if!) I return on 8th November.

Meantime, I'm pleased you all had a good time, and am bitterly disappointed to have missed it. (saw Jimi yesterday - he still looks awful! What on earth did you do to him?)

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Re: F6 mid channel

Do you have instrumentation that gave you that amount of wind? Midday, I was around 50N 01 35W with a couple of reefs in the gene and reckoned it was F4-5. As the tide had just turned West that wouldn't have had much effect on my estimation, so do you think I was underestimating, maybe because I was reaching?

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Re: Cherbourg - one person\'s true story

Yer nae ile painting yersel ye lang streakk o' piss .... humph..

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Re: F6 mid channel

My impression of the Wind Speed was confirmed by the data from the Channel Lightvessel weather station - which was about 30-40 miles away. That gave a pretty constant wind speed of about 25 kts throughout the day on Sunday, which is F6. Similarly the reports from Coastal stations at 0500 Friday morning gave F7 for both Sandettie and Channel Lightvessel.

My own wind instruments are not calibrated - and I know they read low - last weekend suggests they are at least 25% low if not more. Both trips were at much the same AWA and much the same AWS - in my case the average AWS read about 20 kts when they should have been registering high 20s. Tome's wind instruments recorded speeds that seemed more in keeping with F6

Certainly the wind always seems much stronger close hauled rather than reaching - in fact there is a genuine difference in apparent speed of 6 knots (which is equivalent to one force on the Beaufort Scale) and then the much reduced healing motion, and more comfortable attitude to the waves, make it seem easier going

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