How much weight can you swim up???

[wjefferis]

I am working up some bouyance calculations and was curious as to how much weight some of you consider swimmable from say 100 fsw

I would say anything over ten pounds needs to be lifted by a lift bag. This would certainly be the case when lifting items such as a really nice anchor you find during your dive. However if your BC totally failed at a depth of 100 feet and you felt like a box of rocks and couldn't swim up then its time to dump your weights. You can always buy more weight pockets and weights later. You may have to hold on tight to the anchor line towards the top due to increased bouyancy but it would still be worth it.

****as a side note if you are asking this because your BC is really old and crappy, you might want to think about replacing it before you have to put your plan into action .

 

[OceanObsessed]

Please explain the joke, maybe I am slow. If you can add a them maybe consider adding a if you are joking so other know. The guy asked a question, you did not answer but rather implied he was an unfit dive buddy merely because he asked a question. Asking and answering questions is part of SB - I hople:no

GrumpyOldGuy,
The original post could be interpreted like he was trying to figure out how much weight it would take to sink a diver (perhaps is buddy). The joke was aimed at that. I was not implying that he is an unfit buddy as you say. I guess with the variety of personalities we have on this forum I can see where some might interpret things different ways

 

[GrumpyOldGuy]

GrumpyOldGuy,
The original post could be interpreted like he was trying to figure out how much weight it would take to sink a diver (perhaps is buddy). The joke was aimed at that. I was not implying that he is an unfit buddy as you say. I guess with the variety of personalities we have on this forum I can see where some might interpret things different ways

As I said, maybe I am slow, probably dense. I read as you saying it was a dumb question. Sorry I jumped to the wrong conclusion.

 

[OceanObsessed]

... I read as you saying it was a dumb question...

Now that I hear your interpretation I can see where it could easily be interpreted that way. I tend to be extremely sarcastic sometimes and believe me... there are alot of people who don't get my jokes . Sorry I called you grumpy.

Now, lets get back to how to drown your buddy ...

 

[116fire]

Isn't the answer something like "however heavy I am I can make it to the surface" I can get to the surface of a ten foot pool with 50#, and no fins, with a push off the bottom. I can pick 10# off the bottom and tread water for about 30 sec, holding the brick out of the water. A drowning victim is about 10# neg...
Freedivers are quite negative at the bottom of their dives.

 

[Jim Ernst]

In my Advanced Open water class we were doing the lift bag drill.

I was carring the liftbag and 40lbs of attached weight to the surface adding air when needed, When we got to the surface I was very exhausted and our Instructor was busting a gut laughing as I was hanging on to the boat with left arm and being pulled back under by the right arm still holding the bag and weights!!

After I got Instructor to stop laughing and help me, He told us why he was laughing so hard.

He said she (GF/Divebuddy) was letting the air out of the liftbag faster then I was putting it in.:11:

Barry (Instructor) told me he was very impressed that I could carry close to 40lbs to the surface from 45-50 feet.

Now I would think there was some...... Air in the bag helping me , But I did get it to the surface and I thought I was going to die before I made it.

 

[TSandM]

I know I can swim 10 lbs negative to the surface without a huge amount of effort, because I ended up in a class with full 85s, a left post failure, and a lost wing inflator.

 

[RJP]

I think it is a VERY important consideration for those who choose to dive with zero ditchable lead.

Here's a question/tangent on this topic:

Is it de facto bad to dive with no ditchable weight? I don't mean by adding 12lbs of weight to your BP that you can't ditch. I mean not REQUIRING more weight than the innate negative bouyancy of your gear.

For instance, I dive steel 119 doubles on an aluminum plate. Even wearing a dry suit with a 300g fleece and a layer of capilene under that, at the end of a dive I'm still probably -2lbs or so. Accordingly I wear ZERO lead.

I can't tell you how many times people tell me "that's dangerous" and that I should "wear 4-6lbs of lead, in case you need to ditch it."

I beg those people to explain to me how that makes sense, but typically get nothing but dismissive shrugs as if to say "hey, if you don't get it I ain't gonna explain it to you."

So am I off base here - wearing "extra weight" for the sole purpose of "being able to ditch it" makes no sense, right?

I could understand if they said "change your gear so that you're not so negative, and then add some lead to maintain neutral bouyancy, which you can ditch if needed." But that would require essentially switching from HP steel tanks to something like double AL100's. That'd sacrifice 40cf of gas but would "lighten my load" by ~10lbs.

With the redundant buoyancy of a drysuit (and the extra redundancy of a lift bag) I don't see the need to change up tanks. Well, that and the fact that I've already laid out >$2k to double up two sets the 119's...

 

[kidspot]

RJP - uhhh ... you are thinking correctly ... they are not. If you add lead, you are now 8# negative if something goes wrong, instead of 2# negative (or whatever the actual numbers are)With a drysuit, you have redundant bouyancy, so the only way you lose all bouyancy is if you breathe off all your gas (or lose it somehow) and then you have bigger problems anyway. My .02 psi...Aloha, Tim

 

[DA Aquamaster]

Yes that makes wonderful sense...you are 2 lbs neg already but would obviously be safer adding some ditchable weight that you could then drop in an emergency to get you back to being 2 lbs negative. That must be taught in the short bus scuba class.

Dropping weight is vastly over rated. It is not really an option even in most recreational situations and in my experience, when it gets done, it gets done on the surface to quickly add bouyancy to panicky diver. Even then it is not common and I have only seen it done once or twice in 20 years. I also saw a diver intentionally drop his weights underwater only once in 20 years. He was inverted and out of control in his dry suit and dropping weights did not help him recover.

What I have seen uncountable times over the last 20 years are divers who pop to the surface unexpectedly when they lose their weightbelts or weight pockets. Countless other times I have come to the aide of divers holding onto something on the bottom or finning downward to avoid popping to the surface when they lost their weights.

I am not a believer in ditchable weight as it causes big problems in an effort to resovle one that does not really exist if the diver is properly weighted in the first place. On a positve note over the years I have acquired a wonderful collection of weight belts and weight pockets. I have a left or a right weight pocket for a variety of BC models.