Your research submarine is the starting card in Undersea Explorers. Place this card faceup in the middle, and then surround it with 8 facedown ocean cards. This isn’t the final art, but you can see what it will look like. You can see the setup here.
This is your explored ocean. Now you can start searching these cards for creature pairs and special action cards.
Each turn, you’ll draw another ocean card from the draw pile, and add it — facedown — to the explored ocean, as you and your scientist friends discover more of the sea.