Playing Crusader Kings 2 with the Charlemagne expansion, I started a game as a count in southern Greece (Byzantine Empire). I rebelled against my liege, and then against the emperor (note: the magic cheat fairy may have left me a large pile of cash to help me get an accelerated start and hire some mercenaries to achieve this feat with relatively little trouble). Then I slipped over to the north coast of Africa to grab some quick territory.
The only problem, and I assume this is a symptom of the early start date, every where is so under developed that I have almost no boats. Initially I could raise 3 boats in my home province, plus another 6 from a mercenary band. After moving my capital to north Africa, I had just my 3 boats (guess I lost touch with the mercenary band with the boats) and after a couple of decades, my research to get level 1 shipbuilding has crawled along and I can now raise maybe 9 ships plus a handful more from levies. This has left me in a rather annoying position of shipping maybe 1400 troops at a time or marching all the way around the Mediterranean to try and chip away at BE (my eventual goal being a glorious return as conquer after building a mini empire in north Africa).
Is there any way to get a larger fleet available to spare me so many long marches?
Best Answer
As JMR noted, the Decision to Conscript Merchant Ships will be useful to you at times.
In the long-haul a vassalized Merchant Republic could provide you substantial ship levies. The Doge of the Republic has a minimum levy of 25 galleys thanks to his Family Palace and will increase as he upgrades his Palace, cities, trade-posts etc. Keeping him happy will naturally help keep the number of his ships you can raise high.
You have two options, one is to try a forcible vassalization of an existing Republic, which would be complicated somewhat by trying to get a casus belli that won't destroy the republic in the process (anything that ends with you directly taking the duchy will break the republic). The other option is to create a republic.
To create a merchant republic
When you grant a Duchy to a person whose capital is a coastal city the game will automatically create a merchant republic. This page gives some extra tips on choosing a good site for a merchant republic and who to put in charge.