I have talked to the Boomers and have the ballasts and the breather. I swam all around the plane and do not see where, or how, to attach the ballasts to the plane.

Can somebody out there help?

Scott

You go to the plane and put them under the wings...

Yep. When you swim under the wings, you should see some hazy-looking blobs under there- those are the "put ballast ballons here" giveaway indicators. Just swim up to them and you'll see the activation prompt.

I remember spending forever on this...

Me too, I was expecting an "Activate plane" pop-up as soon as I got up to it, just like the Megaton bomb.

I took forever doing this because I was so scared i was going to get attacked by some massive horrific underwater monster. Surely no quest could be so easy without a catch..
But yes as someone said, Under the plane are these weird floaty things, they look like training floats little kids use in the swimming pool. If you look directly at them a [ OPTION ] should show up.

Oh, and for the OP.... GO DUCKS!!!