are underwater routers a thing?

[Michael Thomas <mike () mtcc com>]

I was reading an article in the Economist about a new fiber route down 
the Red Sea from Israel and wondered if there were any branches off of 
those lines and where the routers were for them. The route kind of made 
it look like it was completely at sea, but it would kind of make sense 
to leave them at sea if you could put a router there.

Mike