From The Heretic Knowledge Vault
In the world of Errant Road, the Seeadler are to Rinkaiel as the Gewehr are to Kugelheim and the Eisenfaust are to Port Lorrel: the resident mob that runs things behind the scenes, and uses the city as a base of operations. Since, as far as is known, Rinkaiel doesn't exist in the Poe-verse, presumably the Seeadler don't either.
The Seeadler's main gig is not in Rinkaiel itself, but rather on the high seas, reasonably enough. They control a shipyard in Rinkaiel and both market and crew the ships produced there. This turns out to be of interest to player characters Lucas, Jamie, etc., first when an apparent Seeadler ship passes through while they're at the Waldhaxen Channel, and later, when they come to Rinkaiel looking to rent a ship. Jamie negotiates a rental from a curiously cooperative Seeadler big shot named Gryffyd, who, it is hinted, has his own, not entirely altruistic reasons for the transaction. Later, PC Rhett has some unrelated interactions with another Seeadler man named Quince, who seems to handle some security work on the dry-land side of the outfit.
There are occasional indications that the Seeadler have adapted to their sea-faring ways a little more than some people might be comfortable with.