The navy likes to show reporters video clips of dolphins: the dolphin swims off with a live mine, but instead of dumping it on the Russians and blowing the hell out of them, it comes back smiling with the mine between its teeth. The footage is designed to dispel any rumours that killer dolphins exist. Dolphins have been known to return with live mines, but it’s practically unheard of. Besides, if it all goes wrong, it only costs the navy one vessel and three men, and that’s a risk they’re willing to take. They kept experimenting.