Variable ballast

[freedivernd]

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