Imagine the speed which that beast is travelling at - and observe the singular lack of any noticeable wake formation, never mind that it must be travelling considerably faster than the rules might suggest for displacement craft....
But there again, it is probably a SWASFS (Small waterplane area single fin shark) which does not conform to rules......
(Not to be confused with a SWATFS, or a SWATH, which is a catamaran) /forums/images/graemlins/laugh.gif
Thought displacement craft speed calcs only applied on surface cos to do with wave formation. So maybe sharks etc and submarines have different limitations.