probably a Basking shark, I saw 6 of them yesterday. You see a large triangle like fin that sort of looks like a giant great white but the color is more brownish and when they feed they poke their nose up to the surface some times. (You might have seen a large brown shark too? I am not an expert either but I saw a big brown once and it was huge it looked like a small island)
I posted a few pics once on this thread:
http://www.striped-bass.com/Stripert...ad.php?t=24511
Here is what looks like from below
Hybrid Mode
