sir ROWDY said..
I know an easier way if you have no tape measure or tag on lines;
1. Put harness on.
2. Larks head all lines to back of harness.
3. Put chicken loop over post at beach.
4. Run as fast as you can away from post counting your steps as you go. Your steps will roughly be 1m so if you can remember the number you counted to later you will know the length of your lines. (It's far more accurate if you're running fast, so be sure to run as fast as possible).
No need to thank me.
A more precise measurement can be obtained if you run naked.
