Tidal question

[jimi]

Why is there only one minute between HW Dover and HW Portsmouth on Fri PM when there's normally 30 minutes between them?

<hr width=100% size=1>O wad some Power the giftie gie us
To see oursels as ithers see us!

 

[Guest]

Both PC plotters that I have give 20 - 35 mins between them respectively.

Which reference are you using for your times / which tables ?

Now I am going to click on PBO's re-print of Adm. Tides ...... just to check my PC's !!!!



<hr width=100% size=1>Nigel ...
Bilge Keelers get up further ! I came - cos they said was FREE Guinness !
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[jimi]

Reeds gives 20:59 for Portsmouth and 20:58 for Dover
<A target="_blank" HREF=http://www.ukho.gov.uk/tideprediction.cfm>Easy tide</A> gives Portsmouth 21:00 and Dover 20:59

<hr width=100% size=1>O wad some Power the giftie gie us
To see oursels as ithers see us!

 

[Magic_Sailor]

Hopefully because

Some kind person has moved Portsmouth away from me to the vicinity of St Margarets!

Magic

<hr width=100% size=1><A target="_blank" HREF=http://hometown.aol.co.uk/geoffwestgarth/myhomepage/travelwriting.html>Click for website!</A>

 

[Guest]

Have a gander at ....

The PBO tide bit above .....

Dover is given on 21 November 20:52 6.3m
Ports 21 November 21:14 4.5m

Tide Plotter gives Dover 21 November 2102 6.34m
Ports 21 November 2122 4.42m

??

<hr width=100% size=1>Nigel ...
Bilge Keelers get up further ! I came - cos they said was FREE Guinness !
/forums/images/icons/cool.gif

 

[jimbouy]

Re: Have a gander at ....

Tide plotter 2003

21/11/2003

Portsmouth 21.29
Dover 21.04

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[ParaHandy]

Re: white van man speaks .. ?

look mate, if we can't get the trains running to a timetable why d'you think the tides will be any different or better ... ?

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[Guest]

Time Tables

Why do you have a time table if you cannot keep to the published times ?

If we didn't have a time table - you wouldn't know the train was late !!

Boom Boom


<hr width=100% size=1>Nigel ...
Bilge Keelers get up further ! I came - cos they said was FREE Guinness !
/forums/images/icons/cool.gif

 

[tcm]

Re: Missing 30 minutes

Perhaps the mising 30 minutes was an allowance in the schedule in case last night's game went into extra time?

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[jimbouy]

Re: white van man speaks .. ?

I bet if the swiss had tides they would be on time /forums/images/icons/smile.gif

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[ParaHandy]

Re: Missing 11 players ...

play football like some play cricket ?

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[Chris_Robb]

My premier Marina booklet shows 21:29 - think the other is probably a misprint!

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[jimi]

Looks like it ... or a software error, Easytide also seems to have the same error.

<hr width=100% size=1>O wad some Power the giftie gie us
To see oursels as ithers see us!

 

[Chris_Robb]

Glad to see your doing your passage plan in office hours!!

Weather looks OK - though Saturday looks a little confusing with possible southerlies in the south of the region - Sunday SE 4 - nice reach

Have a good trip

Chris

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[BlueSkyNick]

"Glad to see your doing your passage plan in office hours!!"

Seems fair enough to me - I bet Jimi thinks about work when he's on the boat sometimes (well, at least a little bit, once in a while)

Similarly, I always go to the barbers on a weekday on the basis that my hair grows during office hours, too.

<hr width=100% size=1>People who think they know it all are very annoying to those of us that do.

 

[NigeCh]

Re: Tidal question (An answer)

All places have a +/- 40 minute high tide variation over the year. It's mainly down to the moon. UKHO has developed a set of harmonics that they claim as copyright - But I don't see how they could claim copyright for the Moon.

If you take the time of either the full or new moon relative to where you are then you can create a +/- contstant that is good enough for determinine high tides anywhere (relative to coastal anomolies)

What you've (and most others here have) discovered is that belief in what's printed is fact when it's not: If you look at all the tide tables mentioned in this thread then you'll get a whole set of wierd answers ... UKHO Easytide is not all that good either.

I use Laver's and WXtide (modified) to get to within +/- 20 minutes.

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[Birdseye]

Re: Tidal question (An answer)

"But I don't see how they could claim copyright for the Moon."

Oh, the naivety of youth!! /forums/images/icons/smile.gif


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[LadyInBed]

Re: Tidal question (An answer)

Funny thing this copyright, UKHO publish a book listing all the harmonics and an equation to apply them to, then claim copyright when someone writes a program to utilise the information.

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