Ocean is such a simple map, that brings many complications. No islands means no cover, which means easy line of fires, and easy citadels. Because even if you are angling your armor to one ship, you could be broadside to another.
So, to fully understand how to beat your opponents on this map, you need to see how each ship class performs.
The perfect map for destroyers has lots of islands to retreat behind, but some good space to get torpedoes off at battleships. But there are simply no islands on this map. So all of your tactics have to change. Unless you want to get to the port earlier than the battle ends, you won’t want to fire your guns very often. Every single cruiser in range would pounce on you.
As a cruiser you will know not to mess with battleships at broadside. You will always make sure you face them straight on, while positioning other islands as cover. But with no islands to cover you, there could be a battleship you are presenting a broadside to, even though you are angling at a different battleship. So here comes a full salvo of battleship shells out of nowhere, 3 citadels, back to port.
On any other map, aircraft carriers can hide behind islands. But say you are spotted by aircraft on Ocean. Nowhere to hide, the battleships see a chance of eliminating their worst enemy. Weak armor, you will find that you are soon destroyed.
It seems, as a battleship, this is the perfect map. Destroyers find it hard to be sneaky, cruisers show lots of broadsides and aircraft carriers can be countered a lot easier. But it comes with complications. If the enemy is organized, you can be picked on, and when you are on low health, there is nowhere to hide.
There is one thing that will bring your team to victory. That is co-ordination. This is simply because you can use each ships strengths on this map to cover up each ships weaknesses. Make your aircraft carrier spot your enemies carrier, get your battleships to focus fire, then your cruisers and destroyers to help the needy with smoke.
All of this will help you slowly overwhelm the enemy, and result in victory. Remember that the capture points are not too vital to success, as you can’t just cap then camp on them.