The dissolution of freely rising, 100 to 1000 μm diameter air bubbles was measured in reagent grade water, seawater, and artificial seawater. Dissolution was studied for samples having varied percent air saturation, and temperature. All data were taken at atmospheric pressure. Bubbles dissolved faster in water and artificial seawater than in seawater and there is less scatter in the dissolution data for water than for seawater. The dissolution rate is linearly dependent on percent air saturation and is independent of diameter. Dissolution was measured at several temperatures between 6¿ C and 44¿ C in seawater and is weakly dependent on temperature within this range. The data are in good agreement with theory. Comparison with earlier seawater data taken at higher pressures indicates that a mechanism for inhibiting dissolution is present at high pressures.