There is an old argument that a library is a defense against forgetting. The cartographers of the coast disagree. To them a library is a tide table: it tells you not what will be kept, but in what order things will be taken.
What I admire in the drowned libraries is their honesty. They do not pretend to be permanent. They simply decide, shelf by shelf, what is worth carrying to higher ground — and they let the rest become sea.