Great deck tech. Definitely going to use some of these suggestions in my list. 3 things. First, I believe her name is pronounced "cuh(or coh)-SEE-muh(or mah)". Second, I'd also recommend Karn, silver golem as another animator. Allows you to cheaply, selectively, and repeatably animate your boats. Lastly, as a great way to take advantage of Cosima after she etbs with a bunch of counters on her, Dragon throne of Tarkir. Gives her defender yeah, but she can act as a HUGE anthem for your whole fleet.
Yep, Karn is a great include for the deck, but as a reserve list card, he is way outside the budget I was going for. Love the Dragon Throne suggestion, good one.