For a moving image you can also:
1) Use a single photo and tone-map it. If shot in RAW you might process it twice, once for highlights and once for the darks and then blend just like HDR of two photos.
2) Use several shots - one exposed for the sky, one the ground and one the sea (or one for sea and ground). Thus timed so that the sky shot has the waves at their fall so that when you edit you can impose the wave shot over the sky shot and the waves will cover over parts of the sky. Thus letting you adjust both like an HDR - though you might have to use manual layer masks for this one.
In short you let hte sky be a background and then the wave covers over it