Help

[Mikey B]

Having bought a book called dive Dorset which contains a lot of way point for wrecks etc.

 

Can any one advice on the correct last 3 digits of the Long and Lat as I'm a little confused.

 

For example the Clan Macvey is shown as 50 30 .69 N; 01 46.71 W.

 

Do I enter the last digts as 069 and 071 or 690 and 710.

 

Thanks for your help

 

Mikey B

[Paul D]

Mike,

 

If your GPS is set up to display Degrees Minutes and decimal minutes ( ie. 51 30.69 ) then you would enter 51 30 690.

 

However, I suspect your GPS may be set up to display degrees minutes seconds. In this case you wouldn't be able to enter the above value at all . You then have two options.

 

1) Either change the display mode of the GPS to be in Degrees Minutes and decimal minutes ( ie. ddd mmm.mm ) as opposed to ddd mmm sss

 

2) Convert the values from the book to be in Degrees Minutes Seconds format. ( ie. 30.69 N is 30 degrees and ( 0.69 * 60 ) seconds = 41.4 seconds

 

 

HOWEVER : - I seem to recall Bob F telling me that the co-ordinates in the Dive Dorset book were in OS reference as opposed to WGS. This would mean a further conversion is needed.

 

Bob ?

 

[Mikey B]

Thank you Paul, I look forward to meeting you at the next club meeting.

 

Many thanks

 

Mikey B

[Fugazi]

Mike,

 

I wouldn't put too much faith in the Dive Dorset book as most of the positions given are those recorded at the time of loss. Consider them more rough appoximations of where wrecks might be found than actual verified positions.

 

Gordon H

 

[lady jane]

have a look in boat talk posted 15th march under conversion heading.the book has the wrong info for conversion.

 

cheers andy

[Mikey B]

Thanks Andy, took me a while to find but I've found the conversion chart.

 

Many thanks for the info.

 

Mikey B

[britboard]

if you go to the links page, and into the wreck site there is an automated conversion tool. type in the numbers and click, couldn't be easier

 

Simon L

[sean]

Check at the beginning of Dive Dorset and it is referring to OSGB 36 chart datum but they do explain how to convert the positions to WSG 84 chart datum, as used by most plotters. They also go on to explain the accuracy or lack of it.

 

My 1999 (third edition) suggest adjusting 0.04 minutes southwards and 0.08 minutes eastwards.