Based on where you were, the time of the year, I'd guess this,
http://www.oceanlight.com/html/mola_mola.html
Take care.
Tom
"The beatings will stop when morale improves."
E. Teach, 1717
I have seen plenty of those in the bay and since this one had a tail
sticking out of the water 15 feet or so behind it, rules out a sunfish.
chris....