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Variable ballast
03-25-2003, 10:39 AM,
#1
Variable ballast
Fred,

Do you have any pictures of your set-up? I had thought about making a sled last year, but your's sounds much simpler to make, and use.

Right now I either do constant or free-immersion, on the mooring lines of the local ship wrecks.

I also use my scooter to cover some serious gorund while freediving on the wrecks. More than once I have swooped down to retrieve a lost fin, weight belt or mask from a careless bubble-blower while out on the lake.

I have used it to gain depth without effort, but a weight system seems like it would get me deeper faster- no effort in steering.

Jon
"Ignorance begets confidence more often than does knowledge." -Charles Darwin
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03-25-2003, 08:19 PM,
#2
Re:Variable ballast
Jon,
My variable setup is nothing more than a rope, 9lb diving weight, and an old cable spool. I have it setup so I can hook it to the underside of a milk crate and inner tube. I have several more elaborate plans in the works for a variable setup to use off the boat... a variable setup + incorporated diver retrieval. I have spent a lot of time designing this and hopefully will have a working model this summer/spring. I think my latest design is a "go", just to track down materials now. Another simple variable setup I'm putting together now for surface swimming/diving is just an old cable spool filled with expandable foam (so I can toss the crate & tube), adding handles to crank the rope and 9lb weight up. I find that around 10lbs of weight is all you want to be lifting off the bottom if you're treading water and, if you're ballasted right, 10lbs is plenty to get you there with no exertion.
My boat design will take a lot more weight for an even faster ride down.
Fred
Cold and dark down there huh?
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03-26-2003, 08:53 AM,
#3
Re:Variable ballast
Any pictures that you can post??

Jon
"Ignorance begets confidence more often than does knowledge." -Charles Darwin
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03-26-2003, 10:01 AM, (This post was last modified: 03-26-2003, 10:04 AM by freedivernd.)
#4
Re:Variable ballast
cable spools.. the gray one is the "now" project. Filling with foam, adding fold up rewind handles so I can fold them in close so they don't throw so much water on the un-wind. This should work good.
Cold and dark down there huh?
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03-26-2003, 10:07 AM, (This post was last modified: 03-26-2003, 10:07 AM by freedivernd.)
#5
Re:Variable ballast
Forgive the rough hand drawing.. this is the plan for the boat. I have located the clutch, off of an old potato harvester, that was the main obstacle in this design.
Fred
Cold and dark down there huh?
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03-26-2003, 10:24 AM,
#6
Re:Variable ballast
I should have added that any thoughts, input, criticism, or other ideas, is appreciated, especially on the boat setup.
Fred
Cold and dark down there huh?
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03-26-2003, 11:21 AM,
#7
Re:Variable ballast
I was really curious on how easy it is to reel the whole thing back up while just floating in the water. On a boat it's no problem, but floating on the surface makes things a bit more difficult.

I was thinking about a very simple system for constant ballast safety. Basically a line dropped overboard with about 10 pounds hanging on the end of it. The diver would go up and down it with a short leash attached to their wrist, or weightbelt, and the other end caribinered off to the line. On the surface you could run the top of the line over a pully, since we already have a lifiting boom on our boat, and attach the other end to a big, say 50 pound, weight belt. The diver just goes up and down the line for training and if there's a problem you can just drop the other belt over the end of the boat. The belt goes down and the diver comes up. Just a thought, but it has ver few moving parts.

For now I just find it a big help to have a line that I can haul myself back up on.

This is a picture of how Kirk ran mulitple lines down in Miami.

Jon


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"Ignorance begets confidence more often than does knowledge." -Charles Darwin
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03-26-2003, 11:36 AM,
#8
Re:Variable ballast


Great photo.. living up here it's hard to imagine that there really are many more freedivers!

Jon, I've used a 9lb diving weight quite a bit to get to the bottom for an afternoon of diving.. it's very easy to lift while treading water, that is while being nuetrally bouyant at around -40', so whatever that makes me at the surface.
I know I have started using a descent line a lot more attached to my tube and crate, but mostly just for directional purposes.
Jon, you mentioned a 50lb weight... I'm thinking that on the boat, I would still use around 10lbs or so, maybe 15 for the diver side spool.. I don't think a 50lb weight would be necessary on the weight side spool in that case to retrieve both diver and diver side weight. I think it will be necessary for whoever is in the boat to monitor retrieval speed, and possibly help it along, but I was thinking in the case of diver and 15lb ballast, that only about 30lbs should be necessary to get a diver to surface with ease. Maybe not even 30 lbs, depending on how much the boat tender helps the spools along. It'll definitely be trial and error.
And of course... we're aware of the talk about variable not being the safest because you may not get a true indication of how good a breath up you've had.
Fred
Cold and dark down there huh?
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03-26-2003, 11:47 AM,
#9
Re:Variable ballast
The rope and pulleys was my first design but I ran into problems that weren't so easily solved... I wanted the rope to go through some kind of a one way guide so I could still use a spool for the rope. That way it would work good for any depth. Finding the right setup to let the rope go freely one direction and then being able to lock the wieghts on to pull the rope the other direction was a stumbling block. Plus, I wanted a little resistance on the diver rope so that you wouldn't get a "fishing reel backlash" effect... if that would be an issue, I don't know.
Fred
Cold and dark down there huh?
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