I'm sure you've heard of people putting messages in bottles before and them being delivered to people across the world. What's interesting about this is how extensive the ocean is, how much of the world can be reached from just the coastline, and how the ocean itself can move objects without the need for external power.
But you could improve upon the bottle idea by adding a solar panel; small motor; ardino; disk drive; radio. Messages could be stored in this device in bulk and it would eventually reach other destinations. If such devices were cheap to produce you could have thousands of them in the ocean and have them communicate with each other to form an alternative to the Internet. It would be similar to satellite constellations in that infrastructure could be moved to provide connectivity between routes as strategically necessary.
Is anyone building anything like this?
>SSB was created by Dominic Tarr in 2014 as part of experimental development in alternative databases and distributed systems. Tarr lived on a sailboat with unreliable internet connection, and became interested in creating an offline-friendly secure gossip protocol for social networking.
https://en.wikipedia.org/wiki/Secure_Scuttlebutt