Isn’t this a navigable waterway? How could it just be closed off by end-to-end aircraft carriers?
The two ships are moored facing each other, and you catapult from one deck to the other.
I’m thinking they point the bows upstream and build a bridge between the hulls. Sort of a really big pontoon bridge. Believe it or not, the Persians did in 480 BC and it worked. Naturally you’d be able to navigate under the bridge between the hulls.
The can turn it into homeless housing too!!