The underwater seal drain is the same as used for chest tube drainage. The Replogle tube is sited in the oesophageal pouch and attached to the UWSD unit, which is attached to wall suction. This method is shown in the Royal Children's Hospital Melbourne clinical guideline at the following link https://www.rch.org.au/rchcpg/hospital_clinical_guideline_index/Replogle_tube_management/