A collapsible fire fighting bucket to be suspended from an aircraft and to be filled from an open body of water. The bucket has two means for adjusting the capacity thereof to accomodate load carrying capacity of the aircraft. One means includes sidewall stiffening means in the bucket sidewall which bulge outwardly under load. The second means includes an adjusting means around the side wall for adjustably restricting the circumference thereof and thereby reducing the capacity of the bucket. A bucket assembly comprising a main bucket and a booster bucket is used for filling from shallow water. The booster bucket empties into the main bucket on lifting to give the main bucket a better fill.