Hey, can you I copy your homework?
Sure, just change a few things so it's not obvious.
There's very little I can say about this that has not been said about the sea cat already, but a summary:
-10 RHD bad.
-Animal type bad.
-2 intelligence bad.
-Lack of limbs bad.
-19 strength... not bad, but very below par for a huge 10 HD creature.
-Aquatic air-breather bad.
-20 ft. land speed bad.
The redeeming qualities here are an okay-ish bite/claw/claw attack routine, blindsight, and some natural armor. That doesn't make up for the sea tiger's general crappiness, -0 LA it is. If you really want to be a sea tiger, just play as a druid or paladin and get one as a companion.