It seems like a remote possibility, but believe it or not it is quite possible to come across criminal activity while diving.
The whole idea of underwater criminal activity that involves scuba diving reminds me of some of the older movies (007 movies & etc) that featured underwater battles with divers and involvement with criminal activity.
Well this is no Bond movie or anything like it. It is quite possible to encounter criminal activity below the surface while scuba diving. Just ask Rene Umberger, a researcher, who was severely attacked underwater while documenting coral reef damage. We posted an article about this underwater attack a while back, click here to read it.
More recently a group of divers exploring Kokoya, a remote island, in Indonesia came across a pair dugongs that were roped and caged at the bottom of the sea. These rare animals were apparently being held for paid photo opportunities.
The divers tried to convince the fishermen that captured the animals to release them. At first it appeared that the fishermen agreed to release them, but the divers didn't believe they would be released and so they posted videos and photos on the internet. This tactic worked, and within 1 day wildlife authorities were able to dive down and set them free.
One important take-away from these two stories is to, where possible, avoid underwater confrontation and resolve the issue with the proper top-side authorities.