Actually my buddy told me I'm in error. They calculated each jug to support
25
pounds, so 4 jugs to 100 pounds. I believe Dolly only has two.


A pint's a pound the world around. A gallon of sea water is about 8 pounds. You
will get a significant part of that in bouyancy with a jug of foam.
So about 13 jugs for 100 lbs.
As someone who actively participates in beach and bay cleanup I will also say a
garden variety milk jug won't last that long in the sun and salt water. They
will get brittle and crumble within a year.
The standard float for people who don't want to buy the real dock floats is the
poly drum. They even make hardware to fasten them to the structure.

Things that work "out on the lake" (like that galvanized fence idea) will not
hold up in the southern sun and salt water. By the end of the summer that 16ga
galvanized wire will be a rusty mess. You also may have to deal with some
"named" weather ;-)