This is a secure knot that can be used to tie two ropes together, particularly if they are larger, heavier sized ropes. Because it is pleasing to the eye when tied, it is often used as a decorative knot as well. The Carrick Bend is required for the Pioneering merit badge.
To tie the Carrick Bend, form a basic loop with the larger size rope (blue rope in illustration) and lay loop on top of the working end of the second rope.
Remember the sequence: over, under, over, under, over and pass working end of second rope around first loop and itself following that sequence. Pull tight.