What do you mean by animated? Do you want an animation to play, or do you want to play sea battles like land battles?

The first may be possible: IIRC the Sengoku Jidai team succeeded in adding the S:TW pictures to R:TW messages. However, since their mod is not out yet I am not sure, and you do have to get the animations from somewhere. The second is probably impossible. Back in the early days of R:TW, someone released screenshots of a sea battle mod, but this was never heard of again. Anyway, the engine is simply not suited for this: the battles would play out like chariot/elephant battles on a blue field.