Its time to dust off the cobwebs from the days of scouting, fishing and climbing.
Find the name of the knot, and then the required letter. Convert the letter to a number by taking the alphabet position of the letter.
Click here (or on the image) for a larger version.
The cache is hidden at S29 AB.CDE and E30 VW.XYZ.
Once you have the final co-ordinates, enjoy the hike to a great viewpoint in Krantzkloof.