July 1, 2007: In the United States, the FBI has sent a warning to all scuba diving schools. Diving instructors are told to be on the lookout for anyone requesting instruction in techniques that could be used by terrorists. In short, these are "combat swimming" techniques. While some diving instructors have military diving experience, most do not, and would not normally recognize requests for training a terrorist could use. This includes stuff like how to dive in murky water, or up pipes, or how to handle being towed while in the water with diving gear, or how to use re-breathers, do deep diving and handle diver propulsion vehicles (DPVs). Interest in underwater navigation training is another warning sign, as are those who pay in cash and refuse to give any personal information. Anyone requesting help in purchasing diver propulsion vehicles (DPVs) could also be up to no good.

A lot of these requests can be legitimate. Some people have special diving needs. But if people from a country not noted for a lot of scuba divers, pays cash, and asks for training in arcane diving subjects, diving school personnel are asked to let the FBI know, and the feds will take it from there.

Something is up, or some FBI bureaucrat doesn't want to be accused of ignoring something similar to the pilot training alerts that were phoned in prior to September 11, 2001. The FBI is interested in anyone who has, in the past, received, or requested, the suspicious training subjects.