I think what made it not great for me was that the whole 18th century pirate/British Navy theme felt like only window dressing and at its core it just wants to be like so many contemporary shows you see set in modern times where you have some super smart/capable/everyman action-spy guy go in after the magic McGuffin technology thingy. The setting in this case is just for show and didn't seem to matter much.
Take for example Deadwood, where the setting is everything. ' A wild, anything-goes-mining town struggles to deal with mass change as outside influences (Federal govt and Hearst) seek to take control and reign it in'. Brilliant historical fiction.
So far this felt like Jack Baur starring in Assassin's Creed.