Many different multicolored fish live in the coral reef. The players breed a new generation of these fish. The parent fish need to live in coral, which is found in the flowing waters. The more reef boats a player has, the more chances he has to find suitable fish. One needs to breed a red male and a yellow female or vice versa to produce a red-yellow baby fish.
The 60 reef cards are shuffled. Then the tableau between the players is laid out. It consists of four rows each of 8 cards. The two middle rows are placed face down. The rows near the players are played face up. (See figure on page 2 of the rules.) The rest of the cards are placed face down off to the side.
The baby fish cards are shuffled and placed face down. Four baby fish cards are drawn and placed face up near the end of the reef.
The reef boats are placed off to the side at the other end of the reef. Each player takes one reef boat and places it next to the first row of reef cards. (See figure on page 2.)
The worms are placed beside the spare reef boats. Each player starts with one worm of each color.
Whoever can stay under water the longest goes first. If that cannot be determined now, the oldest player starts. [This is German for "choose a starting player randomly". --Jeff]
One can house two fish (always one male and one female) at a reef in order to make baby fish. In order to breed, the right combination of parents must be used.
If a face-up baby fish card shows, for example, a red-yellow baby fish, then one must place a red female and a yellow male or vice versa at a reef card in order to breed the baby fish. One may not play a second fish at a reef card unless they breed immediately.
Once a breeding is completed, the two parents are discarded and the baby fish card is placed on the reef card. That reef card is no longer available to house parent fish or other baby fish, but it does count against the total of five reef cards. Then a new baby fish card is revealed. The current player may breed the new baby fish if he can perform the necessary actions.
Note: On the fish cards, one or two dots are shown in one corner. They signify how many of that color/gender cards are in the deck.
(Tip: It makes quite a bit of sense to have a shark eat one of your own parent fish if it does not fit any of the baby fish. This is the only way to get rid of parent fish from your reefs.)
All cards other than fish can be purchased with any color worms or pearls.
Hint: There are 15 boat cards, so if one player has 8, the other can only have 7.
Tip: One can use a shark to kill an inconvenient card and all the water behind it if it is going to be the front card in the tableau.
The tableau is refilled from the stock, face down in the center rows, face up in the edge rows so as to have eight cards in each row at the end of each turn.
Note: the deck may be shuffled even if no more cards are needed in the display. [How can this be? --Jeff]
Play now passes to the other player.
She puts the blue male fish on the reef card with the red female to breed. She discards both adult fish and replaces them with the blue and red baby fish.
A new baby fish card is dealt. It is a green/green fish. Anna has no green fish, but has an uninhabited coral card, so she tries her luck fishing in the middle row. She spends any worm (here a purple worm) and flips over a card in one of the rows next to her boats. Good luck! It's a green female. Quickly, she spends a green worm, takes this fish, and places it on her coral card. A green male fish is not to be seen. Since she has no other green worms, she stops fishing.
She still has a shark. She uses it on the yellow male fish in the far row, which her opponent can use for breeding. The yellow male fish and Anna's shark are discarded.
To end her turn, she discards the open water card at the front of the rows and shifts the cards towards the front. She checks for a reshuffle and fills the tableau. She refills the middle rows face down and passes the turn to her opponent.