Bowline

If I were to use only one knot for all my underwater criminal investigation needs, it would be the bowline. I have used this knot more than any other knot and I believe it to be the best knot for overall underwater work. Not everyone has the same faith as I do in the bowline, but you're reading my web page!

Seriously, there are many advantages to using this knot:

• It's easy to tie on land and underwater (with practice).
• It is easy to untie after the rope has been under strain.
• It will not slip or jam when used correctly under normal conditions.

For search patterns, the bowline is normally used to fix a line to an object, like a downweight, or to form a fixed loop at the end of a rope for an arc search.

When I practice this knot, I prefer to use a downweight. This technique ensures that I use the knot correctly and maintain my understanding of how the knot can be applied underwater. If you want to practice and don't have a downweight handy, just wrap the rope around your leg to simulate a downweight.

• Step one - When tying the bowline knot, the first and most important feature is creating your loop. First feed the running end (the very end of the rope) through the eye bolt on the downweight, or wrap the rope around your leg. Then hold the rope up from the eyebolt (or leg) with your left hand. Then with your right hand, thumb down, grab the rope just below your left hand and twist your wrist upwards, making a small loop. Now hold that loop with the fingers of your left hand. This method will make the correct loop every time. Once you have done this, do it over and over again until you can make a proper loop every time automatically. 

• Step two - Grab the running end with your right hand and insert the end of the rope through your loop, coming up from below or from behind the loop (depending on how you're holding it).

• Step three - Pass the end behind and around the right side of the standing part, then back down into your loop. Be sure to give yourself about 6 inches of free line with the running end.

• Step four - Hold the end of your rope and the right side of the larger loop with your right hand and hold the standing part with your left hand and pull to tighten your knot. 
• When you use a bowline, it is important to make sure you tighten the knot and give yourself approximately 6-8 inches of free line on the running end in case you want to add one or two half-hitches to secure it.

That's a bowline, the knot used most frequently by the Underwater Criminal Investigator. Make sure you're proficient with this knot because you'll need it. If you prefer to use a knot like the figure 8 knot, that's fine; just make sure you are proficient in tying it.

Half Hitch

Sheet Bend

Figure Eight