Hello, friends. I am glad to inform you that the Yenisei location is now available in the form of DLC.
https://store.steampowered.com/app/1420500/Fisher_Online/
After purchasing it, you can visit this location at any time and spend as much time there as you want.
Note: after purchasing the DLC, you need to re-enter the game so that the travel to base button appears at the top right.
Keep in mind that fish caught at locations from the DLC do not participate in the rankings and world records are not set at these locations.