This potion is made by using the Fairy + Fish in the cauldron. This potion doesn’t have any stackable effects.
Drinking this potion turns you into a pretty mermaid & gives you the ability to swim around in the air. You aren’t technically flying when you use this potion even though you can move around in the sky.
You can use this one as a cheap & free alternative to a flying potion if you don’t have access to better ones.
This Potion is spell number #34 in the potions book.