[Karl Heinrich]

I've tried to streamline the process here, no images this time so refer to the first post for those if necessary. Again if anything is unclear it's almost certainly my fault, so just ask.

How to work out your position in co-ordinates

Key Data:

• 1 Degree of Longitude / Latitude = 120km
• 0.03km = 1” (second) of Longitude / Latitude
• 0.1km = 3”
• 0.5km = 15”
• 1.0km = 30”
• 2.0km = 1' 0”

1. Measure the distance of your boat from the Prime (Greenwich) meridian using the ruler tool. Keep it as straight as possible. Don't worry if it's slightly wonky.

Example: We measured from the boat in berth at Wilhelmshaven to the Prime Meridian. Our result was 973.2km east of the Meridian.

2. Break the distance down into degrees. As a degree of long/lat in SH3 is 120km, we divide the measured distance by 120.

The whole number then provides us the degree of longitude.

Example: As our measured distance was 973.2km, to need to divide this by 120. So, 973.2 / 120 = 8.11. As the whole number is 8, our degree of longitude is E08.

3. Convert the remainder from Step 2 back into km. To do this, multiply by 120.

Example: Our remainder from Step 2 is 0.11. We convert this into km: 0.11 x 120 = 13.2. So we have 13.2km

4. Convert our remainder distance into minutes, referring to the Key Data. Starting with minutes - 2km is 1' (minute) of long/lat. It is easier to take the highest even whole number from your Step 3 result and divide by 2.

Example: With our result of 13.2, the highest even number is 12. We convert that into minutes: 12 / 2 = 6. So we have 6' of longitude. Our current coords: E08 6'

5. Referring to the Key Data we need to convert the final remainder into (minutes and) seconds. Once this is done we have full longitude.

Example. From the 13.2 we have 1.2km yet to be converted. Referring to the key data we can see that 1km is 30” (seconds) and 0.2km is 6” seconds, so we have 36” in total.

Our full longitude is then E08 6' 36”

6. Carry out steps 1-5 again for latitude, but instead of measuring from the Prime Meridian in Step 1 we measure to the Equator.

Note: when measuring longitude, the rule can be drawn slightly above you position, for latitude you need to draw the ruler from on top of your position.

7. Put the final two results for longitude and latitude together, starting with longitude. Congratulations. You now have your full coords. They should look something like this:

E08 6' 36” N53 30' 36”

There are slightly different formats that we can present this in, but this will work if you put it in Google Maps or similar.