"Prehistoric Planet" has ranked the top 10 dinosaurs, and #1 was a sea monster. I watched this ancient creature leap up and grab a raptor for dinner. Yes, it was an animated replication based on scientific research, but it looked like stuff they hang on the ceiling of the Smithsonian Museum of Natural History -- just moving (and devouring a fierce creature).
The next time someone tells me I shouldn't fear what doesn't exist, I will think of that creature and remember how vast and unexplored are the seas. Once these naysayers prove to me beyond a reasonable doubt that such a creature does not exist even in the murkiest depths of the ocean, I will take their word.
Until then, I will remain convinced they are hanging out with giant squid (which was found off the coast of New Zealand earlier this year) and partying in the deep, reaching up for a meal when needed. I shan't be that meal.