Human and dolphin interactions have occurred since the active creatures were first discovered in the wide oceans. Although there is anecdotal evidence of dolphins helping shipwreck victims and fisherman, more recent interactions are far better documented. Perhaps most interesting is the military’s use of trained dolphins for undersea reconnaissance. Because of their amazingly well-tuned sonar, Dolphins can pick out objects under water and aren’t bothered by competing noises like mechanical sonar is. As a result, they can locate and tag missing equipment, dangers, or even intruders. Along with sea lions, Dolphins are now official members of some naval units.