I placed a chop in each bag, sealed the bag about 1/3 the way. Lowered the bag, bottom first, into the water, until only about 1 1/2 - 2 inches were above the water (not letting any water in the bag). This forced almost all the air out, then I sealed it the rest of the way, while still submerged. Took it out, did the other one. You can do this in a large bowl, pot, what have you.