Prioritize the first couple of Arks over growing your population, to claim resources and strategic positions, as well as gaining increased Essence production from Ark modules.Pass Species Stability as soon as you can, to smooth out your early essence gain. Both the power law, Righteous Fury, and the starting law, Species Stability, are important for Vodyani early game. Try not to lose the party from the senate.
Vodyani get one of the highest bonuses from boosting. Scavenged ramscoop is an especially good module, because its bonus to distance moved is multiplicative.
Whenever you have to move an Ark, try to put just enough engines in utility slots to get it to destination as fast as possible. Send them directions your ships aren't going to explore, it's imperative to find as many minor factions as fast as possible and locate a nearby homeworld