Concepts

 Here is a design for one of the types of turrets.

Body and Base to be done

It's design was inspired by the Steampunk style Gatling-gun and the Sci-fi turret on the right

 

The three barrels will rotate like that of the Gatling-gun, as it stands I have no idea how plausible this is or how it will be done.
I'm going for a Sci-fi based model with a Steampunk texture to incorporate the two.

Ship body concept

Here is a design of the battleship I have done

I took inspiration from a few of our reference images.
(No duh that's what they're there for!)

Such as the Avengers Air ship image that James has put up for the propellers for the lift. I designed that they fold away into an empty space just below the deck.

To aid in the transition from sea to air, I have put three Helium gas canisters on both sides, they are partly embedded into the ship to reduce some of the drag they will cause while in water.

In the center there is the control tower, a radio tower and some smoke stacks for some Steampunk accent.

The 'wing' at the back is for air steering, despite looking at how planes tail fins help turn the plane I don't think the rudder itself would be efficient.

I have done some place holders for the turrets and hidden sphere turrets, this will more than likely change for the final design. The sphere turrets were inspired by these.

As for a basic idea of what we are aiming for the animation we want to show the battleship in the sea, the transition from sea to air and then into battle showing off the turrets.