Being that I have little experience in physics, but have grown a fascination for it, I am hoping you guys can help with a problem. A friend of mine wants to make a few pontoons to make his boat more stable. It's just a smaller 15' aluminum boat that he uses for hooping (catching lobsters). He wants to know how much air volume he needs to float about 300 pounds. How much weight a specific volume of air will hold in water. What exactly would the equation be to figure that out? I'm guessing it's so simple that I've overanalyzed it. I'm hoping that I've made myself clear enoug.