This knot is the main one we use for tying up boats. The round turn takes the load and the 2 half hitches hold it securely. The names gives the way we tie it: A Round Turn followed by a half hitch and then another half hitch.
Instructions for the Round Turn & 2 Half Hitches can be found here:
https://www.animatedknots.com/round-turn-two-half-hitches-knot
