In the United States, divers treat the safety of themselves and colleagues as of paramount importance, yet a marked dissimilarity exists in the importance attached to safety by policymakers. In the United Kingdom, various legislation controls all commercial diving activity and lays down rigid guidelines for selection, medical examination, training programs, and supervised diving techniques. Although police are exempt from this legislation, every police force adopts the principles laid down. The result is a minimum national standard imposed and monitored by the Association of Chief Police Officers. The British Police Diving Manual sets down a minimum scale of equipment per team and per team member. The United States has no universally adopted manual covering police diving. In the United Kingdom, the Diving Manual stipulates a rigid training requirment. Many police divers in the United States receive no formal training, only 'on the job' instruction given by colleagues. Experience in the United Kingdom demostrates that a central clearinghouse for information is essential for progress. The report includes a comparison table of underwater search units in the United Kingdom and the United States. Photographs are included.