When dolphins appear, they will appear on reels 2 and 4, where they replace all symbols except the scattered treasure chest symbol. However, if the dolphins appear on reels 2 and 4 at the same time, they will trigger a re-spin feature where they unfold to cover all reels 2 and 4, while reels 1, 3 and 5 are re-spin five times.
Marine life is playing with you and leaving a lot of floating letters and numbers in the coral reef to distract you - but when you swim, you might collect them all because they will be between 5 and 250 Time to win 3 to 5 matching products.