Reminds me of a story from years ago, I think also in Florida. Couple was off shore and decided a little skinny dipping was in order. Their little dog, alone on the boat, got all worked up as little dogs do when left alone. Running excitedly around the cockpit of the small open boat, he managed to hit the shifter and put the boat in gear.
Luckily the couple was eventually rescued by helicopter and the boat and dog were recovered OK too.
This stuff really does happen. Glad this ended well.