This page offers a guide on grabbing the Shine Sprite in Episode 6 of Ricco Harbor. This area is accessed via the Rainbow M on the side of the Boathouse on the west side of Delfino Plaza once you’ve obtained at least 3 Shines and defeated the Polluted Piranha.
Collecting all 8 Red Coins
The objective for this Shine Sprite is to collect all 8 Red Coins situated on the water of Ricco Harbor, easily done by using the Bloopers you used back in Episode 2. Start by heading to the right to the edge of the pier and leap onto the giant red button to cause the 8 Red Coins to materialize. Now choose a Blooper to ride, opting to stay away from the Pink Blooper as handling is more important than top speed.
Start by following the Gold Coins and collect the first 3 Red Coins before heading towards the tunnel entrance to locate the 4th Coin. Continue following the Gold Coins, sticking close to the left wall and you’ll come across the 5th Coin near the buoys. Take a sharp right turn and follow the Gold Coins towards the yellow submarine, jumping to reach the 6th Coin but taking care to steer around it to the left.
Keep an eye out for the upcoming red platform and go under it to snag the 7th Coin before looking ahead to the two boats where the 8th and final Coin is. The Shine will then appear back on the pier so head over towards it and leap onto the pier to score another Shine.