Tidal Height Calcs

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cod

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Looe 0300BST 27th June

Tidal height effected by barometric pressure but not by any other meteorological influences.

Barometric pressure 968Mb

If you draw 1.7m and require the obligatory 1.0m CL. What is the minimum depth to anchor in taking it that you are going to leave for Plymouth the following morning.



I should add this is a theoretical situation. I do not want anyone running aground in Looe on Monday morning!!!!!

MINESAPINT.
 
I spect everyone is gleefully rushing off for their tidetables to do some secondary port calculations. NOT!

NOTE: Your special RYA tide tables (from which I think the "correct" answer to this question is derived?) aren't the same as 2005 tide tables, or those for any other year. They're made up. The only reason you wd have your RYA-issue tide tables are for rya exam questions, but once the exam has been done it's almost a liability having the "exam only" ones around - the same goes for the charts - cos they're all made up and nothing to do with reality. Hence - hardly anyone else will the info - except for rya instructors who are unlikely to do all the work for you via internet forum in a sort of free corresponsdence course, nice people though they may be....
 
The question has nothing to do with RYA.

It is real from current edition of Reeds OKI 2005.

The only discrepancy I would expect is between different sources of tidal predictions. ie Admiralty verses Proudman.

MINESAPINT.
 
What an amazingly silly question.

Looe is a drying harbour so the only place to anchor is off the rocky shore. It's the middle of the night, there's a major storm in progress and shelter in Plymouth or Fowey is only a couple of hours away.

Has to be a wind-up.
 
Can you just ignore the fact that it is a stupid question. It is not an RYA question, there is no text. For the sake of argument the weather is perfect and there is a suitable anchorage within the area that would be covered by the secondary port information for Looe page 214 of REEDS OKI 2005.

Additionally could you provide the actual height of tide at the appropriate hour, 0300BST?

MINESAPINT.
 
In perfect weather! My answer is the same. you anchor in the designated anchoring area. You can't miss it as if there is any shortage of water the fishing fleet will all be anchored off and they all draw the same or more than you. if no fishing fleet, anchor just to seaward of the line of yellow bouys that protect the leisure area. In the dark there is a transit between lights that will put you in the right spot.
 
I have been in to Looe and dried out and reckoned that the best to leave when the boat floated...whatever the barometric pressure was.
Couldnt find South Coombe Island though...
 
ah, right

so, you don't need this in info, and/or you already have the info, but in any case you pose the question primarily (if not entirely) for your amusement.

No problem bout that, cept that when you really DO want some info - people will assume it's just another question for the sake of it, won't they?
 
Re: ah, right

I think I know the answer. But I would be pleased to see someone confirm it.

I dont seem to be able to win one way or the other. The way I see it is I will be happy to have my answer confirmed and in the event of a difference of opinion re the answer we will be able collectively to sort it out. Anyone who has no idea what we are on about might be happy to learn the principles involved.

MINESAPINT.
 
Keep it under your hat then, see if anyone else gets it. If you like PM me with your answer.

MINESAPINT.
 
You misunderstand me. The answer is that I would never anchor at Looe with the barometer at 968mb. There is no other sane answer.

Incidentally, your 'obligatory 1m' is anything but. I anchored yesterday in a river knowing that I would touch bottom at low water. If I were anchoring off Looe in rough weather I'd want a good 2m under me.

This reminds me of a story from a master's exam...

"You are anchored off a lee shore in force 4. The wind increases to force 6, what do you do?"... 'Veer a shackle of chain'

"The wind now increases to force 8, what do you do" ..'veer another shackle of chain'

"It now increases to force 10" ..'Veer another 2 shackles of chain'

"Where are you getting all this chain from?" ..'Same place you're getting all this wind.'
 
Re: ah, right

A large proportion of the threads on this forum are hypotehtical and no one seems to mind. The difference in this case is that no one knows the answer, and no one likes to look stupid.
 
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