Problem is OP is now Naval Action is facing stiff competition. SOT, this, black wake, hearts of oak, etc all look a lot more exciting compared to the OW aspects of Naval action to the average gamer. I suspect the real reason behind the legends beta that they are starting this summer. The current swell in popularity of AOS/pirate themed games is going to potentially put a dent in NA's population.
I seriously doubt the combat they come up with will compare to NA's, but how many want to mess with the other aspects NA open world has to offer.