In the latest dev diary, Hear of Iton IV developers have gone over the core introduction of the planned changes to naval gameplay, and they look exciting, to say the least.
The most obvious change is the first port of call today, and that is the tech tree. There are a number of changes here.
So firstly the naval tech tree has been split into 2, the naval tab contains hulls and tech directly linked to hulls. Now, it's much more concise than before, armor techs have been combined so each level will unlock both heavy and cruiser armors and are not linked to any specific hulls. SH armor still remains part of the super-heavy battleship.
In the Naval Support tab, you will see quite a difference from the old tech tree. Gone are the secondary battery techs as they are now research via the medium gun techs.
Additionally, Dual-purpose guns now branch off the light gun line. They are a 1939 onward tech, with the UK, USA, Japan & France starting with the Basic dual-purpose Battery Researched and historic ships starting equipped with dual-purpose Batteries and dual-purpose Secondaries. Dual-purpose guns lack the piercing of regular guns but make up for it by also providing AA.
Finally, there is the 1944 Advanced medium dual purpose battery which packs a punch both to ships and planes, which, should you reach it, could wreak havoc for enemy aircraft and destroyers alike.