Agreed, good job all around. Great (what must be) CGI for the battles; fortunately the movie has substance too- when someone recommends a movie and all they have to say about it is "The special effects were great", I usually don't bother with it.
Anyone who liked this might like Das Boot, about WW1 U-boat combat from the POV of a sub crew. In that war, members of the submarine corps had a survival rate of 25%. Watch that one when you've got some time on your hands though; it's over 3 hours.