DIR - Frequently Asked Questions

[And]

Hi

You mean the Herriott Watt university study published on Divernet? Yep, yellow flags were decided to be more conspicuous, so long as you were in the right postion to the wind. I do not know the parameters of the study but that is what they said. I do know that they did not test yellow SMB's, which we all carry as emergency SMB's but in the recommendations they say it may give as much visibility as a flag.

Orange SMB's were seen more than 1km away. We do carry yellow smb's too, and of course lights with plenty of burn time and backup lights with even more burn time should the surface cover not be there when reaching the surface and if light is failing. An orange SMB is also signalling your position perhaps as much as 1 hour before any flag will do even if doing a relatively short deco dive.

The primary consideration is the surface cover. It is pointless having a yellow smb to signal an emergency if your surface cover is unreliable and more than 1km away. That is integral to the team approach and one of the conclusions was that as the observers had more experience they spotted the signalling devices quicker and more accurately. So pick experienced skippers with high recommendations.

Andy

[Jeremy H]

I don't want to get involved in whether it's good DIR practice to carry one or not (I don't know, myself, other than to say I carry one and on a couple of occasions it's stopped a problem developing(!))

I've often chatted to skippers about colours and i think that Divernet test was conducted from a helicopter. The skippers I've chatted to have said in many cases that they prefer orange to yellow but several have commented that black is actually normally most visible. (Never had the courage to try it myself though!) Most lobbie pot flags are black though?

Perhaps there's a difference in squinting at the horizon (from a boat) and looking down onto a greeny-grey colour from a chopper?

Regards

jeremy

[Mark Chase]

Knowing Mark I know he likes bottom times of 40 mins or so and taking that to its conclusion you are talking inwater time of well over two hours, more like three.

Andy

My longest run time so far is 155mins which was 40mins at 68m. I have never had the back gas available to push much past 2 1/2 hours diving. Even this dive ment having a third travel gas to get me down and then up to my first stop and I still left the bottom on 50 bar.

3 Hours is a long dive and there is nothing preventing you carrying seporate OC deco gas.

The new pre cast scrubbers for the insperation/kiss will be 8 hours.

ATB

Mark Chase

[wreckweasel]

Originally Posted by Mark Chase

dive and there is nothing preventing you carrying seporate OC deco gas.

The new pre cast scrubbers for the insperation/kiss will be 8 hours.

My ass will they, that sounds like serious marketing blurb to me!

[Brass Monkey]

Originally Posted by Mark Chase

The new pre cast scrubbers for the insperation/kiss will be 8 hours.

Where did you here this Mark? I would be very interested in reading about them marketing hype or not.


Dave.

[Freeflow]

Originally Posted by NotDeadYet

With a passive SCR you need to monitor gas being dumped, in a CCR you need to monitor a handset, where is the difference?

On a passive SCR, you don't moitor gas being dumped, but you do monitor gas left in the tank, like you would on OC, CCR, MCCR.

In the original post the use of a particular SCR was mentioned, but no name was given, which model is it?

And finally, on SCR you can use it as OC by inhaling through the mouth and out through the nose. The downside is that you are only on a 5L cylinder if you dive a Dolph like I do.

[Tricky]

Originally Posted by Freeflow

In the original post the use of a particular SCR was mentioned, but no name was given, which model is it?

The Halcyon RB80.