SHE DANCED topless on a submarine sailing out of Port Canaveral, Fla. The crew cheered. The Navy brass booed. And the sub skipper was stripped of his command.

Cathy "Cat" Futch, then - in a demonstration either of patriotism or contrition - joined the U.S. Marines. That career was almost as short-lived as her shimmy on the USSE Finback because even before the boot camp rigors of Paris Island were completed, Futch received a medical discharge two months after enlisting. For ulcers.

Now almost two years after her notorious go-go routine, Futch, who is 19 but sometimes boosts her age by a year or two or three, is occasionally tending bar around the Florida coast.

Only last month she was working at the Club One, a neighborhood hangout in Nims, Fla., where a fully costumed clown opens the door. Futch was reportedly giving ber $1.75-an-hour earnings to her mother in Titusville, Fla.

A call to the Club One only turned up a gruff and dispassionate answer. "She hasn't been here in a week or so."

Drifting has always been her way. She ran away from her rural Georgia home at age 14, had a brief marriage to a Navy man and earned her living as a go-go dancer. When the submarine incident exploded into a barrage of publicity for Futch, she said, "I know quite a bit about the Navy and I never saw such a ssihiling bunch of men go out to sea. I really boosted the men's morale. It didn't hurt them or me."

She tried dancing again, but was vexed by leering patrons who would yell, "Hey, Cat, I've got a surpressing feelings about the attitude of the Marine officers toward her.

Recently she told a reporter in Miami that she wants to reenlist in the Marines, further her education. Futch should have her way because she also boasted that she's a good shot and keeps a freezer full of venison.