Moving in 2d rts

Hello everyone, please tell me if someone has come across, you need to implement character relocation in a 2d rts game. Initially, the character appears on the island and can only move on the island, there is water around. But over time, he makes a boat and can only move on water on it. me sprites of land and separately water. maybe someone has come across this or someone has an idea how best to implement this. I will be very grateful, thanks in advance.

Not sure if I understand this, but I think you want collision layers, you can make collisions so that the boat can not go on the land and the player can not go in the water.