Knots have been used by man since nearly the dawn of time for trapping and hunting. The oldest known – used in a fishing net found in Finland in 1913 – dates from around 8000BC. Knots became more useful to man when the Age of Sail began in the late 16th Century.
The advent of the Boy Scouts movement in 1908 brought the use of knots to the populace at the turn of the 20th century.
Today there are thousands of types of knots but they fall into 3 distinct categories – loop knots (knots with just one rope), bends (rope to rope knots) and hitches (rope to object knots).
We have three core knots that, as a Scuba Diving professional, are useful to know. They are the ‘Bowline’, ‘Sheet Bend’ and a ‘Two Half Hitch’.
The bowline is a simple and ancient knot used to form a loop at the end of a rope. It’s is easy to both tie and untie and has a reputation as a reliable knot but can work loose when not under load. You may have heard before that the ‘rabbit or snake’ (it looks more like a snake than a rabbit) comes out of the hole, around the tree and back in the hole. The main issue here is making the hole the right way round.
An easy way to do this is to hold the rope vertically in your left hand whilst your right hand holds the rope between thumb and forefinger and ‘starts the car’ or turns the rope clockwise to form a small loop – here is your hole for the ‘snake’ to come out of. Once the ‘snake’ has been around the tree and returned to its hole you need to tighten the knot by holding the head and tail of the snake in one hand and the tree in the other and pull gently. Ta Daa!
The Sheet Bend
The sheet bend is a popular knot that ties two ropes (typically of different thicknesses) together. It is a very secure knot which is quite fast to tie. A very straightforward knot to tie with a few common mistakes.
Firstly pulling this knot tight can be problematic if you pull the wrong ends.Do not pull the end of the rope at right angles to the main knot.
The second main issue is to not bring the second rope back under itself and mistakenly trying a reef knot, which is shown above.
The Two Half Hitch
The two half hitch is a very useful knot that secures the rope to a pole, boat or mooring ring or used for attaching fenders to a boat. Although two Half Hitches do make a complete ‘Hitch’, it is sometimes better to begin by first passing the rope around the object a second time to make a round turn. This is more secure and provides easier control of the load while tying the Half Hitches.
The main problems here come from tying the actual hitches in two different directions. The hitch should be tied the same way twice i.e. clockwise or anti-clockwise.
The Search & Recovery Speciality Course
You’ll get to practice these knots during the Search & Recovery Speciality Course. This course goes into detail about specific search pattern that apply to different situations when something is lost at sea.
The pattern you use will depend on a number of factors – size of lost object, visibility, bottom composition and depth.
The Expanding Square search is used when you have a specific start point for the search whereas the U shaped search pattern is used when you know the rough direction of the lost object.
Once you have found the object, this is where the knots come in by securing the object to a lift bag, ready for recovery. There are many different types of lift bag available depending on the size of the lift required – the general rule is that if it weighs more than 4 kg you should not use your BCD to lift the object, you should use a lift bag.
Knots On Other PADI Courses
The Search & Recovery Specialty is a very useful course which will give you credit when you continue on to certain Pro Level courses. The PADI Divemaster course has a number of practical applications that you need to complete and one is a Search & Recovery Scenario. You’ll practice a number of search patterns, re-tie the three knots and will ultimately demonstrate how to safely rig and bring to the surface and object that is no more than 10kg negatively buoyant.
On your Instructor Development Course (IDC) you may be asked to make a Search & Recovery presentation, in Open Water, which will either focus on knot tying or rigging and lifting.
How Do You Get Better At Knots?
In a nutshell – practice, practice, and practice. If you are keen a scuba diver, check out the PADI Search & Recovery Speciality course. If you are a budding PADI Pro then you will get more opportunities to practice these knots on both the Divemaster Course and IDC.
Author: Justin Mayers (PADI CD #472708)