Yes!!!! lvl 18 potions.

[Sven Osymthe]

On Test I leveled up by using the swift foot potions, as well as growing grog. I'm not sure if those are good now (I'm only 14 on Live), but that way helped me master first on Test.

As others say though, Port Royal is the best for simpler potions. Cuba, Padres and Tortuga all add in a fourth ingredient, making the game more challenging. What I've been doing on Live has helped me level up quickly also, use up some potions, remake them. If you don't wanna do that, just try to get 5 of every type.