Piranha

A young couple discovers an abandoned military site with a large swimming pool, unaware that it is populated by mutant piranhas created for a secret experiment called “Operation Razorteeth.” A private detective and an alcoholic mountain man join forces to stop the fish, but discover that they are threatening a summer camp and a tourist village along the river. As they try to raise the alarm, they are thwarted by those who want to cover it up, and the piranhas wreak havoc before they can intervene.
At the beginning of the film, a couple undresses at night in front of a swimming pool. Janie Squire takes off her shirt and remains topless, then pulls down her shorts and shows us a little bit of pubic hair before adjusting her panties. Finally, she dives into the water. Unfortunately, this is the only nude scene in the film.