How much weight can YOU swim up?

[drbill]

Anything over 20# is a PITA for me. I once was on a 200 ft dive off Ship Rock when my BCD bladder sprung a major leak and had to swim up with 38# on my belt (I over weight for filming). Although I don't know what the actual net weight was (givren my wetsuit buoyancy), it was a royal PITA and I later bought a dual bladder BCD. I've had to retrieve a 24# weight belt dropped off our dive boat by a customer and it was a difficult task even with my sturdy tree trunks... er, German legs (I wear split fins... no comment please).

 

[fdog]

Around 25lb with Jets (wet), massive RMV and pending heart attack IMO Jets are not great for this, maybe some free-diving fins will show better results :cool2:

Good thought. I own 3 pairs of freediving fins, all of them tend to "flag" (bend and flap in the wind like a flag) at high loads:

Sorry it's a terrible photo, but you can see my fins folding up with the force from a strong dolphin kick. These C4 VGR 81 fins are designed around low O2 consumption, so they are fairly soft, and thus flag easily.

I also have a pair of Mundaial Competitions which are at the upper limit of stiffness for a freediving fin. These, too, flag at high loads like a 20 lb weight belt (although not as easily as the C4 VGR 81's).

The length of freediving fins also interferes with a fast cadence, so my experience is they have a "thrust ceiling" no matter how powerful your legs are.


Flagging is not just something you see in freediving fins. IIRC these are AquaLung Carravelle fins:

My observations have been that once a fin has flagged, the only way to get more thrust is to kick faster.


I don't believe that "flag resistance" (I just made that up ) should be the primary metric in fin selection. Each fin design is a series of compromises, and optimizations.

The thoughtful diver will select a fin that fits their primary diving needs, and just note the amount of thrust they can generate; then, plan other things, such as ditchable weight, around that.


Hope this helps!


All the best, James

 

[SailNaked]

I did ~25# once found it on the bottom while snorkling at ~45ft, almost had to drop them to get to surface.

People do not compensate for different situations when calculating weight. I saw some divers in shorties and AL80 with 24#s, I asked them if they needed that much weight, their answer "yes that is what we use" they were swimming straight up and down looked like running not swiming. Ill assume that in canada in a 12mil suit that is what they were given in their OW course to stick them to the bottom.

thanks to SB people can think about it a little more and make better decisions.

 

[Diver0001]

...I bet you'd be surprised.

I posted this because of all the interest lately in weighting, and amount of ditchable weight.

Every winter I do a "scuba tune-up" mentoring session. One thing it includes is swimming up a variety of weight belts in the deep end of a pool. Because I've tried it in a lot of configurations, I know that I can swim up:

• 5 lbs is easy. Not even noticed. Yawn.
• 10 lbs is just a strong kick.
• 15 lbs is a strong kick and fast cadence. It's work but not difficult.
• 20 lbs is difficult with a whopping RMV. Doable but we're talking a RMV of 3 or more.
• 30 lbs, I can barely do this, but only by executing short, 12' sprints.

This is for me, 6' tall and 200 lbs. swimming with a powerful kick with Jetfins or Quattros.

Something I've noticed is a diver with split fins tops out at 20 lbs, no matter how good their legs are. The same for the fins that bend to produce thrust, like Volos or the Scubapro Seawings. Each person is different, you have to actually try it to know how much you can swim up.

I would submit that part and parcel of determining ditchable weight is A) how much you, personally, can swim up, and, B) the maximum potential negative buoyancy you may encounter in an emergency.


All the best, James

Thanks for starting this thread, James.

Never tried it because I don't tend to overweight myself.

I'm thinking, just based on things that I've experienced during training, that 6kg / 12-14lbs is about the limit of what I could hold up for any length of time. If I'm more or less *just* positive on the surface and someone were to hand me off a 6kg weightbelt then I'd have to work hard to stay on the surface with it for any length of time unless I inflated my BCD.

As for what I carry. My weightbelt normally has 4kg on it for salt water, which is marginally more than I need. In fresh water I would need 2kg to be comfortable but I could do it without weights at all with breathing tricks. That's the maximum amount of dead weight I'd have to hold up for any length of time.

R..

 

[Laurie S.]

Just got back from Mendocino where my fiance and I were freediving for abalone. He had to ditch his weight belt and I had to remove mine since it was slipping off. I could see his belt in less than 10 feet of water and went down for it, pulling myself down the kelp. I couldn't bring it up, but it was 35 pounds, which is why he ditched it. He forgot about his recent weight loss. It took another diver (big guy) and me to bring it up.

 

[Doubler]

I have swum up full double steel 85s. That's probably about 15 pounds. I would absolutely never want to swim up any more than that. It's not so much the swimming up, as the "How do I stay here?" once you get to the surface.

You dump the tanks.

 

[TMHeimer]

I guess it depends on what thickness your wetsuit is (can't comment on drysuit) and how much (if any) air is in your BC on the bottom. I do a lot of 20-30' shallow dives in my 7 mil farmer john wearing 41 lbs. with my AL80 tank (yes, I actually need that much weight as I have experimented a lot with less to no avail), split fins. I find I can usually swim up from that depth. If my BC is empty to start I believe I must add a little air so it will expand. Same thing with 36lbs. and my steel 72 tank. I don't dive deep very often, but can't really recall having to add BC air on those occasions.

 

[fdog]

TMHeimer, I should clarify that we're talking about additional, dead weight.

In the pool, the divers get neutral, then, we hand them an extra weightbelt. They attempt to swim up the extra weight without adjusting their buoyancy.


All the best, James

 

[TMHeimer]

TMHeimer, I should clarify that we're talking about additional, dead weight.

In the pool, the divers get neutral, then, we hand them an extra weightbelt. They attempt to swim up the extra weight without adjusting their buoyancy.

All the best, James

Gotcha. I probably could not swim up carrying an extra 41 pounds......

 

[Dr. Lecter]

In the pool, the divers get neutral, then, we hand them an extra weightbelt. They attempt to swim up the extra weight without adjusting their buoyancy.

What's the purpose of such a drill? I would think you'd have them get fully negative (zero air in wing to expand during ascent, to simulate truly catastrophic wing failure) and then let them experience the difference between trying to swim up a balanced rig without a wing and swim up X # of extra lead. As described, they're going to get some benefit from the expanding gas in the wing as they ascend.