In a situation in which shinkaisei-kan's HP drops to 0, this ship is 「sunk」 and lost. When a ship sinks, no possible remedial actions can be taken. Please bear in mind there's no way for them to return, and pay close attention when engaging in battle.

There are certain conditions that need to be met in order for a ship to sink during the battle. If you put her through a lot of hardships, and expose her to heavy damage, the possibility of her being sunk is high. It is crucial to repair hurt shinkaisei-kans in 「Docking」 and to replenish them with 「Natural Gas」 and 「Fish」 in 「Supply」. Allow them to rest enough at repair and supply, and with all possible measures...

Wow, that's pretty harsh.

I'll have to make sure their HP doesn't drop to zero...