Feel free to add to this page if you think it's missing something. A hybrid is a combination of 2 or more types of ships. They are almost always combinations of the main three ships (subs, carriers and battleships) but you may occasionally encounter others. They idea is that they can combine various traits of their types and get the best of both worlds.
Unlike some other in-game ships, these ships did exsist (albeit in low numbers). Some famous examples include for battlecarriers the Ise class, Tone class, IJN Oyodo, Kiev class and HMS Furious before she was converted into a full carrier. Submarine carriers include the I-400 class, M-3 and Type B class submarine, while a submarine battleship type was the German Underwater Cruiser. Though it is true that the French Surcouf was a gun-slinging, plane wielding submarine, her float plane was used for reconnaissance, not attack.
These are the most common hybrids as you simply need to get and ordinary battleship and add a runway. Also it is the only combination that doesn't involve submarines, and submarines make things a lot more complex. If the hybrid has enough planes and guns, it can be a formidable foe. The playstyle may differ, for it is determined by the nature of the ship.
If the said warship was a minor conversion from a battleship, then play the ship as if it was a battleship. The aircraft here are simply helpful diversions or portable air defense. However, if the ship is simply a heavily-armed aircraft carrier, then play the ship like a standard aircraft carrier. The ship itself is a diversion and the main target, where the aircraft are the main force of the attack. A combination of a few heavy guns and a large aircraft carrier fleet makes this vessel a long-range devastator.
This type should not be confused with dedicated aircraft carriers converted from battleship hulls or vise-versa.
These are far rarer than battlecarriers due to the temperamental nature of subs but they are probably the next simplest hybrid after the battlecarrier. When using them, launch all your plane (if you dive with them, they die) and rely on them to cripple or immobilise the enemy before moving in like you usually would. It is reccomended that you select and 'islands' map for battles to allow yourself time to launch your planes. If facing a Submarinal carrier, shoot down the planes then behave like usual against a sub, dodging torpedoes and then depth charging it.
These are rather redundant since the use of surface guns require a submarine to be surfaced, removing its advantage. However, for those who want to use it, you should equip it with long range guns (probably a mk45 as these are small but have a 15km range) and fire away at them, from a distance, relying on your superior range and distance to keep you safe. Once they have been crippled, you can become a usual sub again. Alternatively you could do the opposite, crippling them with your torpedoes and then finishing them with guns. If you choose this method, make sure you only surface when ALL you enemy's guns have been destroyed. If you find yourself against one, charge at it as distance is its friend. It would probably dive into the safety of the water so then treat it like a regular sub. If it surfaces, it should be a single shot kill for you.
It is very rare, but some Cruiser-Submarines are actually very tough(for a sub). One example is the Surcouf II(by ej2333). It is possible for a submarine to achieve more than 1950 toughness and be armed with 46cm guns. Some submarines can actually reliably engage a Destroyer or Light cruiser im a surface battle.
These are the rarest hybrids due to the shear complexity of it. However, due to the nature of submarines, such a combination, while impressive, is indeed impractical due to the fact a submarine stays underwater (only staying on the surface to launch aircraft, rendering the use of heavy guns useless) and design compromises which make it less capable as a carrier, battleship and submarine. However, it is worth building one if you find showing off skill more important than actually spending money on something useful like a dedicated battleship, carrier or submarine.
So a hybrid seems to be that perfect thing, combining the strengths of two different types of ship. You can can however also exploit the weaknesses of the two types when hybrid hunting. I hope this page helped and please leave your feedback below.