Ballistic missile pods, an angled and a non angled variant. Capable of engaging at extremely long distances and can fire in a barrage instead of a salvo. However, it'll take a long, long time to reload. Angled version basically works as a super long range mortar for surface-air purposes.
Also, as has been suggested many times before, an actual big naval gun with a sweep of ~120 degrees. It's footprint as represented in screenshots 2-5 is 8*11*3, so big, big. I tried to make the shape of the model in the Hawkeye style but I think the caliber is a tad small in comparison to the M3.
Also there's
this, and
this