"A dead turn and two half keys never let go!"
It is the simplest node, the fastest and which leaves all the situations. If you only need to know one, it's this one. You'll never be ridiculous to use it on a boat or a pontoon.
Even if it is considered not very elegant, it remains very effective to moor or to fix a fender. It executes quickly, even if the string is under tension and is released as easily.
Use without moderation!
Start by making a complete dead turn
Then we realize the first half key (a simple knot)
Then comes the second half key identical to the first.
