There is new exclusive content to The Fisherman (4 new fish, a new fishing technique and a new river).
It runs on separate servers, characters and multiplayer are completely different from those in Fishing Planet.
Licenses are unlimited and bought with in-game credits.
Travel + day fees + gear repair fees are 50% cheaper.
Items from Events, Sport and other DLC are available in the in-game store.
Tournament themed DLC can be purchased by baitcoins in the Packs menu.
All of the items from the currently released DLC, which can be bought with baitcoins from the in-game shop in The Fisherman.
It’s pay to own (there are no microtransactions in the Fisherman).
While not exhaustive, here is a detailed list: What is different in The Fisherman compared to Fishing Planet? Previously we mentioned some of the differences between The Fisherman and the free to play version of Fishing Planet.