How much weight can YOU swim up?

[fdog]

The purpose is to burn in the difficulty of swimming up dead weight, and how surprisingly small that amount is. It is nice to have a number to compare with future fin changes/leg strength/etc.

It's true that there is some expansion of air in the wing as they ascend, but this is after we've put in some work to get them weighted correctly; they're in a pool, so the expansion amount isn't much, percentage-wise; and the amount in the wing is very small.

Most seem to have maybe a couple pounds of air in the wing, so they might gain at most a pound of lift as they ascend.


All the best, James

 

[Tigerman]

I can swim up way more than I need to and MUCH more than I want to - Thats kinda all that matters. However Ill say that whenever I dive a steel tank a "catastrophic bcd failure" wouldnt be catastrophic as Id also be in a drysuit..

 

[scubamama]

Something I am gonna have ta try in the pool with both sets of fins. I have a solid and a split set.

Ascending with more weight than you started with is dependent on many factors. While all the posts I read here are great and good information, the perspective for evaluation of this issue is what those factors are. In my opinion the following are all important factors for each diver individually since none are the same.

BCD lift capability - Lots of different setups out there. I have extra lift capability in my BC in the event I have to take a student to the surface or pick up a lost weight/belt and I know what that lift is.

Personal body weight - Yeah, we all know what that means!

Dry, Semi-dry and wetsuits - There are literally thousands of these on the market and all are different. Easiest way to determine how much buoyancy yours has is to place the suit in a pool and add weight to it to determine how much it takes to sink it. Then you will know how much buoyancy it adds to your lift capability (add to your BC lift number). Am not sure about a dry suit and I have no experience using one since I dive in Florida. Hopefully someone out there can answer the question as to how much lift a dry suit has and how to gauge it.

Weights - Again every diver has his own number of lbs for weighting. Subtract this from your lift capability numbers.

Other equipment - Are you diving with a camera, speargun, or any other equipment that is added on? Most cameras usually add a little buoyancy, spearguns take it away because most are negative.

Just some things to think about. No diver has the same statistics as another. Do your homework for yourself and you can determine what your lift capability is within a close proximity.

Hope this helps!

---------- Post added October 16th, 2013 at 09:41 AM ----------

My bad.....Also makes a major difference if you are diving in fresh or salt water! Apologies for omitting that important factor!

 

[Yank]

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).

Wow. All of that. 38#,200ft, and a failed BCD. And below 60' the wetsuit's gotta be compressed. That's a hard swim - must have used a lot of air.

 

[shoredivr]

Doppler (Steve Lewis) here on SB has a method for determining buoyancy of you and your exposure protection (whether drysuit and undergarments or wetsuit) vs the weight of your gear. He writes aboit it in "Six Skills", a very useful book.

Put on your exposure protection, and see how much lead it takes to sink you in shallow water. I curled up into a ball and put weight across my lap.
Get a fish scale. Assemble all your gear, minus the exposure protection, with full tank(s), and immerse in water so the gear is not touching the bottom. I put mask, jetfins etc in a mesh bag. Hang the gear off the fish scale to determine its weight. Full tanks are the maximum weight you'll experience at the beginning of a dive.

The difference between the two determines how much lift you need in your BC.

 

[Frosty]

Fdog--interesting thread.The swimming up bit.are you swimming straight up or swimming up a slope?

 

[billt4sf]

It's not so much the swimming up, as the "How do I stay here?" once you get to the surface.

I intended to find out tomorrow.

But what I really need to know, is not how much I can swim up, but how much excess weight can I keep stabilized at the surface while I orally inflate? Isn't that the point of the question? Because if I can't keep it stabilized at the surface, I need to dump it before even trying, right?

- Bill

 

[fdog]

Kazbanz, swimming straight up.


All the best, James

 

[GrumpyOldGuy]

I can do 24lbs, I retrieved a buddy's weight belt and did not want to use my BCD to lift in case I dropped it.
I don't want to have to do more than that, it was difficult, much more than expected.

 

[Nemrod]

...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

So, now how much can you swim back to shore or boat against current and waves? Now, lose a fin or two, oops.

N