Which of Sea and Wave Incense is better?

Question

Which one is better?

Answer 1

If you want an Azurill from breeding, you should use a Sea Incense. If you want a Mantyke from breeding, use a Wave Incense. There are no differences as held items other than that.

Source
Source

Hope I helped!

Answer 2

They are identical in battle
They both have the same effect of boosting water attacks. The difference is that the Sea incense lets Azumarill/Marill breed for an Azurill, and the Wave Incense lets Mantine breed a Mantyke.

Source:Experience and Bulbapedia