Tackling a lack of boats

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?