He successfully delivered Cindy Preisel's baby boy, even though the baby's feet emerged first.
"I'm no doctor, but even I knew that's not supposed to happen," Keisel said.
"I reached with my fingers... as gently as I could and popped out his left shoulder and then his right," he said. "But then the little guy was stuck by his head, being strangled. So I did the only thing I could - I waited for a contraction and then slid my fingers in around the top of his head and scooped him out."
But the newborn wasn't breathing, so Keisel gently administered CPR.
"I started giving mouth-to-mouth, three short puffs, and then thumping and rubbing its back," he said.
The baby began to take short breaths, and after 20 to 25 minutes of CPR, gulped in air. His lips turned rosy and he started crying.
The baby wasn't due until mid-September.
I won't even spoil this by asking what she was doing out on a boat this close to term.