Cave diver collects samples (IMAGE) Northwestern University Caption Advanced buoyancy skills are required for taking sterile 1-liter water samples. A diver uses an air hose to completely void the sterile bottle, which is then inverted and flooded with the sample water, with the specific depth recorded from wrist mounted depth gauges. Credit Natalie Gibb/Under the Jungle Usage Restrictions add credit License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.