If I was a military historian...

I would write a book about navies quickly built from scratch and proved victorious.

(1) Rome in the Punic Wars, who went from no navy to a navy that defeated the Phonecians / Carthage to become the superpower of the Mediterranean.

(2) Agrippa who built ships in a lake, practiced in seclusion, and then dug a canal to carry the ships to sea, ensuring one victory among several to transform a lad named Octavius into an emperor named Augustus.

(3) Peter the Great, who drug a reluctant nation into the Baltic--a nation with no navy nor desire for a navy--to take land from Sweden that would soon become Saint Petersburg.

Some of my details may be off, as I write from memory. I'm sure there are other similar stories I haven't read about.

What a book that would be!