Master of Waves

Use your devotion to blue as the triggered ability resolves to determine how many tokens are put onto the battlefield. If Master of Waves is still on the battlefield at that time, its mana cost will count toward your devotion to blue.

Mana symbols in the text boxes of permanents you control don't count toward your devotion to any color.

If an activated ability or triggered ability has an effect that depends on your devotion to a color, you count the number of mana symbols of that color among the mana costs of permanents you control as the ability resolves. The permanent with that ability will be counted if it's still on the battlefield at that time.