With the addition of the second sea, there are dozens of things to do here, ranging from catching new fish to exploring the new islands. While these are interesting, at first, you will eventually get tired and will want to return to the first sea for specific things like enchanting your rod or more. So, if you are confused about how to re-enter the first sea, let me help you out.
To return to First Sea in Fisch, you must speak to the Sea Traveler NPC at Waveborne Island (X:440, Y:85, Z:792). You can find him standing between the Egg Salesman and the Innkeeper of Waveborne, wearing a Cthulu uniform. Speak with him, and he will take you back to the first sea in the game. He won't charge you for the travel, and you can immediately return to the first sea.
To re-enter the Second Sea, you have to interact with the Sea Traveler NPC at Terrapin Island ( X:144.3, Y:150, Z: 2035), who will immediately take you to Waveborn Island in the Second Sea. Like the previous traveler, he will also not charge you a single penny. Also, if this is your first trip to the Second Sea, you must fight and defeat the Cthulu Boss. You can do this with the help of the Keeper's Torch and changing its flame color using the multiple shrines/lanterns around the battle area.
Once you have teleported back to Second Sea, you will spawn there each time you log inside the game. However, it is best to change your current spawn island to any of the Second Sea Islands to be on the safer side. I recommend paying some money to the Innkeeper at Waveborne Island to stay there.
For more on Fisch, Check out How to enter Second Sea in Fisch – Sea Traveller, Cthulu & Cursed Sea, or All Fishes in Second Sea (100% Bestiary) – Fisch
