There is no solid validation as to how a Ship girl can become an Abyssal Ship in the first place.

However, the fact as to why one of our ships appears when an enemy is destroyed,

whether they are just ships that were lost at sea and return again or are born again from the sea,

so far I thought I had no physical evidence or testimony to prove it to anyone. Until now.

Drop Ships don't have any memory, no recollection... Neither do Abyssal Ships.

If the Abyssal really used to be ship girls, then their memory might have been wiped out and refreshed.

It's not any different from our "embed the information about the original ship into the brain when they are built" process when we build the ship girls.

The condition of the ship when someone picked her up would be exactly the same as when she was built.

Although, I heard that rarely, the ship will vaguely remember something, though for how long, I can't really say.

And before long, as the rust starts to rub off, like floating soap bubbles, those memories just go bust, quietly disappearing without a trace. As to why, nobody knows... Even the reason why we built you. What an irony, isn't it? Perhaps, since most of us are fighting an enemy we know nothing about.

However, who, or what, you were in the past is better left unknown... Sometimes there's just something best kept in the dark in order for one to start anew.