What type of knots are best for securing two lengths of rope together?

The double fisherman’s knot and the square knot are both excellent choices for securing two lengths of rope together, making this option the best answer.

The double fisherman’s knot is particularly effective for joining two ropes, as it creates a strong and secure connection that is ideal for use in climbing and rescue operations. This knot consists of two overhand knots tied around each other, forming a reliable bond that can withstand significant load without slipping.

The square knot, also known as the reef knot, is another common knot for tying two ropes together, especially when the ropes are of similar diameter. While it is not as strong under certain loads as the double fisherman’s knot, it is easy to tie, untie, and inspect. However, it is important to note that the square knot can become unstable if the ropes are of unequal thickness or if there is significant load variation.

Combining these two knots provides versatility in various rescue scenarios, catering to different requirements for strength and security, making this combination an optimal choice for tying ropes together.