Posted by Kendall Raine on November 13, 2000 at 19:21:15:
In Reply to: Re: DIR question (long) posted by Gerry on November 13, 2000 at 17:48:34:
Gerry;
You really put thought into this. You also made some really good points. I know you wrote this to Mike, but I'm going to take a shot at responding. I'm skipping over the first two paragraphs since they're polemics.
3) Standardization. Polemics aside, you're right, DIR was developed without recreational uses in mind. So what? I've used the same OW single tank shallow water DIR rig for photography and wreck diving. Absent the doubles and a couple of reels, it's the same configuration. Works great. Specifically, what did you have in mind. How does the jacket BC, UK800, octopus in a retaining strap some old place rig work better?
4) If you don't like the long hose, fine. The long hose in OW has certain advantages, but you're right, it really only becomes critcal in OE's. As for an entanglement risk, I used to think so too when I stuffed my long hose along the side of my doubles. Now I wrap it DIR style and, again, it works great and stays out of the way. In fact, it's more streamlined than using a standard 36" hose.
5) I'm confused by this paragraph 'cause it loops around. Anyway, whoever said what, having the ability to control the amount of weight dropped to that which you need to manage a controlled ascent is the key. One way is to have multiple ditchables. The other way is to have a portion non-ditchable. Using one great honking weight belt-like so many divers in California-is a recipe for an embolising, boat-running-down, Free-Willy-breaching-whale, Polaris-missile cluster f@ck.
6) I don't like the keel weight and don't use one.
7) Empty ain't the issue. The issue is max negative buoyancy. There's about a four + pound negative differential between a full AA 72 and a full AL 80. Given the potential for panic from a failed BC on the new diver, why wouldn't you want that guy to have a little negative bupyancy to overcome as possible?
8) Quick releases are a failure point. They can get broken just by people stepping on them or having tanks set on them. Quality is fine but plastic is plastic and steel's real. In many cases the cracks can be hairline so you don't see them untill you're coming up the ladder and the thing fails sending the tank falling on the poor bugger below you. A failure at depth is at least a major hassle and can get worse from there. Finally, quick clips are sewn in. Have one fail far from a sewing machine and you're diving is a lot less fun from then on. As for getting someone out of webbing in an emergency, if the straps are properly adjusted, a rig can be slid off easily. If they're too tight, the webbing can be easily cut.
As requested, no snottyness. Over to you.