This first video shows the underwater view of a hanging ballast experiment. This is with 2 steel weights of 10 lbs each.
This video shows some dry land testing. First I just swing it like it swung in the water. Next we balance it on a bar and see how much weight on a side it takes to tip it. Then we try 4 separate 5 lbs weights (so same total of 20 lbs). This is not stable at all and can not even balance the bucket.