Dive Op Self Defense

[Meng_Tze]

..
In contrast, being underweighted generally prevents the diver from leaving the surface in the first place. I understand that the air in the diver's tank has weight, and that it's conceivable that they would be able to descend at the beginning of the dive, however, for a single 80 foot tank, you're looking at about a five pound swing between full and empty, so no matter what, if they descend they're less than 5lbs underweighted. Furthermore, in this scenario, they would have no air in their BCD, and the extra weight of the air is lost gradually, and so they gradually drift upwards to the surface.
One could argue that the diver could swim down and maintain depth with propulsion, and though certainly this is somewhat risky, the fact of the matter is that most divers will not do this, or get tired of doing it very quickly, or burn through their tank quickly. In any event it certainly limits the time spent at depth.

I was more thinking of being under weighted in the sense of being able to make a controlled ascent. Gas and Buoyancy swing are over weighted easily, but I would rather be overweighted by 5 pounds than underweighted by that amount not being able to hold depth. But this now seems to go outside of the original question. The point I was making is that many professional focus on over weighting, rather than also looking at the flipside of that coin.

 

[wreckchick]

I know I'm jumping in late to this but I think that everyone needs to understand that the average SB diver is NOT the same as the average diver.

I have more people tell me they don't know how much lead they need than are even trying to hazard a guess. Lots of divers have no idea how to set up their gear. There are people that get offended at the idea that 10 years is a long break in diving. You'd probably be surprised at how many people don't even travel with a mask, much less a full set of gear. I don't want to say that they're all clueless, exactly, but there are plenty of warning signs to people that have worked in the industry.

The people that show up with all their gear (with some notable exceptions) and have a rough idea of how much weight they need and can set up their own gear may not be great divers, but rarely do I actually think they pose a threat to themselves, others, or me. There are plenty of divers to really be concerned about while leaving that group alone.

Rachel

 

[DandyDon]

Wow!

I have more people tell me they don't know how much lead they need than are even trying to hazard a guess. Lots of divers have no idea how to set up their gear. There are people that get offended at the idea that 10 years is a long break in diving. You'd probably be surprised at how many people don't even travel with a mask, much less a full set of gear. I don't want to say that they're all clueless, exactly, but there are plenty of warning signs to people that have worked in the industry.

Former divers...trying it again.

 

[Steve_Dives]

Why didn't you just research the bouyancy characteristics of each tank and make the necessary adjustment?

I dive in the university's pool and use the university tanks. While they are all AL80's, they have different characteristics. Sometimes I grab one that is a little more buoyant.

 

[highdesert]

On a trip last year, the resort owner came by as my son and I were gearing up for a shore dive on our first morning. They have a policy of requiring new or inexperienced guests to take a short "skills demo" dive prior to going off alone. She quickley sized us up by asking how much weight we wore. (The minute she asked the question I knew what she was doing, but there is no way out of that one). We passed, no "skills dive" necessary, but I thought it was a great question. - Chris

This question bugs me when we suit up the first time on a trip. When I say "20 pounds", they inevitably tell me that's ridiculous, I don't need anywhere near that weight. When I tell them that at 6'3" I weigh 230 pounds, more of it than I want to admit being, uh, "low density tissue", and that with 18 pounds I'll float to my eyeballs in a buoyancy check, then they get the clue that I've done my homework and been through the drill before.

 

[Fish_Whisperer]

Yup. My instructor is a large man and needs a buttload of lead, but he's been diving since 1987, and has over 5,000 logged dives, and the guy is pure grace in the water... Incredible.

 

[ONESPEED]

I believe they have what is called a 'log book' which should be stamped and initialed by the dive shops and DM where and when one dives. Other than that I would think that you would have to belive what the diver tells you. I suppose that there are some leading questions which you could ask to get an idea if the guy is telling you the truth. A good reason to have them sign a waiver before they dive. In any case, I would imagine that I would be carrying a heavy insurance policy if I were in this business.

Log books can be embellished, not to mention I have been diving for almost 30 years and never logged a dive before last year.

Also, as for the statement I highlighted, 99% of my dives have been from private boats, how do you propose I get a signature and a stamp?

 

[Aquanautchuck]

[QUOTE Also, as for the statement I highlighted, 99% of my dives have been from private boats, how do you propose I get a signature and a stamp?[/QUOTE]

You do what I did and have Justleasa make you a stamp. Since I dive most times solo from my Zodiac I still keep a log for myself and friends when they come along.

Here is a copy of the stamp she made for me.

Charles

 

[Fish_Whisperer]

Hahaha... What a great stamp! VERY nice!!