Yes, the battleship world has the setting of underwater projectiles, and armor below the waterline can also penetrate damage. Sometimes you will find that there is a high-damage core area that does not show that a projectile has hit the enemy (for example, the total damage of an armor-piercing projectile after hitting the core is 1 1000, but the explosion damage is 19000), indicating that an underwater projectile has hit. Although I don't know why there is no underwater bullet hit icon in the battleship world, if there is a sudden injury that exceeds the expected amount of damage, it is basically an underwater bullet hit.