Question: what are blue coins for in super mario sunshine?
Answer: Blue Coins serve a much bigger role in Super Mario Sunshine. In Delfino Plaza, at the Boathouse, 10 Blue Coins can be traded in for a Shine Sprite. There is 240 Blue Coins in the game (30 in levels, 20 in Delfino Plaza and 10 in Corona Mountain) so there is a total of 24 Shine Sprites obtainable from Blue Coins.