Knots must earn their worth aboard your boat. In order to be worth their salt they must:
- Hold fast under all conditions
- Come apart easily when you want them to
You must do your part with respect to knots. You should be able to tie them as automatically as you do your shoe laces. The reason that you don’t have to think about tying your shoes is something called “muscle memory.” The muscles in your fingers have been flexed in the same manner so often that your brain doesn’t have to send individual signals to all the muscles involved. The memory appears to actually lie in the muscles themselves.
Knots obviously introduce kinks into a line that can diminish its strength. Some knots introduce tighter kinks than others. A three-strand line that has been tied with a knot that causes a tight kink can lose up to 30 percent of its strength. This loss of strength can cause a line to part more quickly under strain.
The reduction of line strength varies with the knot. Some examples follow:
- Anchor bend: 24 percent
- Round turn and two half hitches: 30 – 35 percent
- Timber hitch: 30 – 35 percent
- Bowline: 40 percent
- Sheet bend: 45 percent
- Reef knot: 55 percent
See also: Marlinespike for Recreational Boaters