Why two backup torches as a minimum?

[ahar]

Been running through some stuff in preparation for DIRF at the end of Jan, and one thing has stuck me as odd - the requirement for two backup torches. I understand the need for one backup torch per team member but why two?

The two backup torch thing is mandated at the DIR F level so there has to be a reason at every level of diving, even those dives to 30m or above in open water. If two backup torches are not needed for DIR F type dives, then why make it mandatory, as one of the precepts of DIR is only taking the kit that you need along. I can't see its a configuration issue needed for later training as the way that the DIR kit is rigged there is already space for two torches.

Given that all resources are team resources, why two per member - in a team of three that'll be six backup torches! In the very very unlikely event of both your primary and backup torch failing, you would stop. The team member(s) would quickly realise that your torch cannot be seen and stop, so you could swim to them and get their backup. If that then fails, someone up there doesn't want you to be able to see where you're going (!) and you could just ascend anyway keeping in touch contact - remember, this is DIRF level so no overhead and no deco.

Also, remember the DIR requirement for kit maintenance and testing backup torches before the dive - one of the precepts of DIR is that kit mustn't make up for poor technique - making the failure of a primary and secondary light that much more unlikely.

What have I missed?

[jb2cool]

2 torches will make you symetrical and you will look cooler

Even cooler if they are black :D

[Roel]

I have no idea why you should have 2 back up light during your fundies.

During cave you need 2 each. Basic rule is three light sources per person, but the sun is also included in that.
This ruled is based on old statistics with failure rates for lights.
I don't have my cave manual with me but with 3 lights it was something like a 0.1% change of no light during 1000 dives which is considered acceptable.

With my 2 led back up lights I consider that change smaller, but that's fine with me.

Anyway, as far as I'm aware you should have 1 during fundies, although 2 years ago I had none and that was fine with Andy.

Roel

[Alex.Hellwag]

Just in a cave, I´m relieved to know that there is a secound in a situation without my main light.

DIRF with 2 BackUps gives you exercises/practices in the ease of handling.
Remember: These are the fundamentals for the next steps...:D

Have fun - Alex

[Bob Cooper]

You don't need a backup light for DIRF.

Where did you see that?

You need 2 backups for Tech and Cave.

Bob

[davy]

It's nice to have at least 1 BU light...
It keeps the right D-ring down so it's much easier to clip off your light or long hose...

[Clare Gledhill]

Equipment Requirements - for DIR F from the GUE website


Each student should have, and be familiar with, all of the following required equipment.

1. Tanks/Cylinders: Students may use dual tanks/cylinders connected with a dual outlet isolator manifold, which allows for the use of two first-stages. Students may also use a single tank/cylinder with a K, H, or Y-valve.
2. Regulators: One of the second-stages must be on a 5- to 7-foot/1.5- to 2-meter hose. One of the first-stages must supply a pressure gauge and provide inflation for a dry suit (where applicable).
3. Backplate System: A rigid and flat platform, of metal construction with minimal padding, held to a diver by one continuous piece of nylon webbing. This webbing should be adjustable through the plate and should use a buckle to secure the system at the waist. A crotch strap attached to the lower end of this platform and looped through the waistband would prevent the system from riding up a diver's back. A knife should be secured to the waist on the left webbing tab. This webbing should support five D-rings; the first should be placed at the left hip, the second should be placed in line with a diver's right collarbone, the third should be placed in line with the diver's left collarbone, the fourth and fifth should be affixed to the crotch strap to use while scootering or towing/stowing gear. The harness below the diver's arms should have small restrictive bands to allow for the placement of reserve light powered by three in-line c-cell batteries (where necessary). The system should retain a minimalist approach with no unnecessary components.
4. Buoyancy Compensation Device: A diver's buoyancy compensation device should be back-mounted and minimalist in nature. It should come free of extraneous strings, tabs, or other material. There should be no restrictive bands or "bungee" of any sort affixed to the buoyancy cell. In addition, diver lift should not exceed 50lbs for a single tank and 80lbs for double tanks. Wing size and shape should be appropriate to the cylinder size(s) employed for training.
5. At least one depth-measuring device
6. At least one timekeeping device
7. Mask and fins: Mask should be low volume; fins should be rigid, non-split
8. At least one cutting device
9. Wet Notes
10. One spool with 100 feet/30 meters of line per diver
11. Exposure suit appropriate for the duration of exposure

Note: Prior to the commencement of class, students should consult with a GUE representative to verify equipment requirements. Whether or not a piece of equipment fulfills GUE's equipment requirement remains at the discretion of GUE and its instructor representatives. Participants are responsible for providing all equipment or for making provisions to secure the use of necessary equipment before the start of the course. In general, it is better for the student to learn while using his or her own equipment. However, students should exercise caution before purchasing new equipment to avoid acquiring substandard equipment. Please contact a GUE representative prior to making any purchases. Information about recommended equipment can be obtained from the equipment considerations section of GUE's web site.

[ahar]

Ah yes - it seems I've mixed up sections 2.1.2.10 and 2.2.1.10 in the GUE standards pdf(http://www.gue.com/classroom/standar...ds_2003v2a.pdf)

I was looking at the Tech 1 equipment rather than the DIRF requirement.

D'oh.

Oh well now we're here, is the reason that Roel (statistical failure rate of lights) the reason for two backup lights at levels beyond DIRF?

[Gary Moffat]

On another note regarding backup lights.

Always bugged me this as we have standards for everything.

Which backup do you deploy first left or right?

[neilh]

Quote: (Originally Posted by ahar)

The two backup torch thing is mandated at the DIR F level so there has to be a reason at every level of diving, even those dives to 30m or above in open water. If two backup torches are not needed for DIR F type dives, then why make it mandatory, as one of the precepts of DIR is only taking the kit that you need along.

I would have thought if the dive is likely to use your primary light you would take at least one backup. If the dive required your primary (cave, wreck penetration, night, etc) then you would want two backups.

If you were doing an open water dive during the day with good vis you could probably justify not having two backups (there might even be a case not to bother with a backup at all unless you can see it ).

Having said that the backup torches are small and tuck neatly out of the way, so if I had two I'd be tempted to carry both :D