Did Lockheed make design changes to the Havoc 8x8?

I've been looking at this photo of the Havoc from swim tests out at Pendleton.

I can't tell much because they did a good job of hiding it behind a wall of water....but I did pick up on two things.

First, at the last Marine Day they had a manned, legacy AAV turret in place, it appears that they've switched to a RWS.  Next and I can't be sure (I've been comparing photos all morning) but it looks like the swim vane has changed.



I watched the video of their previous (private) tests that they released and my only guess is that they're trying to improve on swim performance.  Quite honestly it looks like they satisfied all Marine Corps specs right out of the box but perfection is desired by their head shed I reckon.

What has me scratching my head is this.  Could a change in the shape, thickness etc...of a swim vane improve water performance?  I don't know.  Hopefully a YAT-YAS guy can fill the blanks.