Tuesday, 5 March 2013

HOW TO: TIE A LOOP ON A PRIMARY LIGHT

Why have a loop on the primary light?
At certain points during a dive it may become necessary to clip the light head off to free up your left hand for a skill.  Such skills include (and are not limited to) DSMB deployment (see picture), switch to deco/back gas, stage bottle rotations or even primary light failure.  Now we could clip off the torch using the P-clip attached to the right hand side of the Goodman Handle however if we did this the light would point directly into a team members’/dive buddies’ eyes.  To prevent this we clip the light off at the rear so it faces down and away from our team members’/buddies eyes.  Hence the loop; it allows the diver to temporarily clip it away with a double ender.  This also gives the added bonus that we can still use the torch for communication if required. 

People have asked me how to do this so while I had a torch in front of me that needed doing I thought I’d show everyone.
You will need the following:
1. Approximately 10cm of 5mm bungee (it needs to be 5mm, not smaller as the loop needs to be rigid enough to stand upright on its own).
2. 60-100cm of cave line (the stuff from your spool).
3. Lighter.
4. Scissors or a sharp blade. 





Tie an overhand knot into either end of the bungee…
… and form a loose loop (approx. 2p size).  Take the cave line and wrap it around the end of the light ensuring it goes over both ends of the bungee.
Take a further 2 wraps around ensuring it is nice and tight; it can get a little tricky.  Do not worry if the bungee loop is not at its biggest as we can resolve this later.  We then finish the knot in a similar manor to how we learnt to tie a boltsnap. 
To do this we cross the 2 ends over and tie an overhand knot on one side.
Next we’re going to tie a reef knot to secure the boltsnap. Remember left over right; right over left.  Tie the knot as tight as you can as it will help the loop stand upright making it easier to clip off.

If I need to I can now pull the loop to ensure it is as large as possible so each overhand knot is touching the cave line and the loop is as large as possible.  To finish, cut the ends off as close to the knot as possible ensuring you leave a few millimeters.
And melt the ends with a lighter, flattening them with the base of the lighter.  This will stop the ends from fraying and reduce the risk of the knot coming undone.
The end result should look something like this
















The boring bit!
All opinions expressed in my articles are my own and may differ to other instructor’s and agency guidelines; by no means are they wrong and I would not wish to disrepute any of them.  This article is for information only and should not replace proper training.

Safe diving!

Timothy Gort
BSAC, PADI & SDI/TDI diver training
l Mob: 07968148261 l Email: tim@rectotec.co.uk l