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Conversion


lady jane
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I WOULD APPRECIATE SOME HELP ON THIS.

IN THE BOOK IT SAYS THAT TO CONVERT FROM OSGB 36 TO WSG 84 YOU NEED TO ADJUST 0.04 MINUTES SOUTHWARDS AND 0.08 MINUTES EASTWARDS !

IF YOU COULD SHOW A CONVERSION THAT WOULD BE GREAT.

 

OSGB 50 38.60N 01 55.57W ?

 

CHEERS ANDY

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The link here is to a spreadsheet that will convert these for you.

Conversion Spreadsheet

 

First you have to change them to decimal units ( I am assuming they are in Deg Mins )

 

OSGB 50 38.60N 01 55.57W = 50.6433 N 01.9262W ( OSGB )

 

Using the spreadsheet converts these to WGS84 as 50.64381 N 1.92759 W

 

or in Deg Mins = 50 38.63 N 01 55.66 W ( WGS84 )

 

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I WOULD APPRECIATE SOME HELP ON THIS.

IN THE BOOK IT SAYS THAT TO CONVERT FROM OSGB 36 TO WSG 84 YOU NEED TO ADJUST 0.04 MINUTES SOUTHWARDS AND 0.08 MINUTES EASTWARDS !

IF YOU COULD SHOW A CONVERSION THAT WOULD BE GREAT.

 

OSGB 50 38.60N 01 55.57W ?

 

CHEERS ANDY

Andy, it is sorta bad manners to use upper case letters all the time when on group messaging, that's why some folk have been asking you not to SHOUT biggrin.gif

 

I know getting used to a keyboard is not as easy as it looks, but we've all been there mate smile.gif It is after all just practice, and practice makes perfect biggrin.gif

Why not give it a try? smile.gif

 

Mad Mike

 

 

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Andy,

 

You can also use your plotter to make the conversions for you.

 

First, set the plotter to the OSG36 datum (rather than WSG84) and set the co-ordinates to Degrees Minutes and Seconds (rather than Degrees and Minutes).

 

The coordinates you have shown above appear to be in degrees minutes and seconds because the last two digits do not go over 59 (60 seconds). If any of the last two digits were 60 or over, they would be in decimal, in this case you would use Degrees and Minutes.

 

Next enter the coordinates you have shown as a waypoint and save it. These are now OSG36 coordintates.

 

Now change the Datum back to WSG84. When you select your waypoint again you should notice that the numbers have changed because they are now being shown in WSG84. You can also change the coordinates back to Degrees and Minutes so that you can see the decimal figures.

 

It sounds like you are taking the coordinates from the Dive Dorset book. These numbers haven't proved to be very accurate for many members. What wreck are you looking for?

 

cheers

 

BF

 

 

 

 

 

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bob,

thanks for your idea and yes your right im trying to work out from d-dorset last edition which says that marks are i degrees,minutes and decimal.

the wreck avanti is one that i was trying to convert, ive tried the conversion but the numbers look wrong!

cheers andy

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Unless I've missunderstood:

 

50 38.60N must be in Degrees, Minutes and Decimal of minutes. (can't have 60 seconds)

 

Therefore to move it 0.04 minutes South, it becomes 50 38.56'N

 

Likewise 01 55.57'W, moved 0.08 minutes East, becomes 01 55.49'W

 

Or have I been doing it wrong all these years?

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This is starting to ring a few bells.

 

I seem to remember that the Dive Dorset conversion is wrong.

 

Instead of 0.08 eastwards I think it should have said westwards.

 

Brian, yes you are right about the 60. Didn't notice this, so the numbers

must be decimal.

 

BF

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I think that would be correct Bob. The spreadsheet calculates the change as just over 0.085 degrees West ( see my earlier calc ).

 

I am tempted to lift the calculation from the sheet and write a web page to do this. Could be useful.

 

SO do you agree with my calculation of

 

50 38.63 N 01 55.66 W ( WGS84 )

 

 

 

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I've just had a look at my Dive Dorset book and I've crossed out the "southwards" and put "northwards", and crossed out "eastwards" and put "westwards", so they got both directions wrong.

 

So, OSG36 50 38 60N and 01 55 57W would be approx 50 38 64N and 01 55 65W in WSG84.

 

Add 0.04 minutes North and 0.08 minutes West.

 

So, yes I agree with your calculation, Paul.

 

I've also just checked it with Martin's conversion tool and got the same result.

 

BF

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The Dive Dorset Book was written over 20 years ago and some of the wreck positions given in the book were obtained from the original records filed at the time of loss, not the actual verified position. Just out of interest, I dug out my old copy to have a look at the position given for the Avanti and found it

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Gordon,

 

It must be nice to have a visual image of the marks you're fishing over, and knowing where you've seen fishing lying. I expect big things from you this year... wink.gif

 

Andy,

Going round in circles and not finding anything was what prompted me to dig deeper into their numbers and uncover the error. Having said that, I still haven't found the numbers to be very accurate. You really have to do a wide search when you get to the rough area. It's still a good book for information on the marks, though.

 

BF

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Bob,

 

Knowing where the fish are and catching them are two different things.

 

Most of last summer there was a shoal of large bream hovering over the Betsy Anna bows, but trying to anchor in the right position to fish for them was impossible. Problem being that I couldn

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