During your return to Gatma Atoll you are faced with a task to locate and heal (with your pulsar) three fish; a Manta Ray, a Humphead Wrasse, and a Manta Whale. These are located at grid marks C3, G2, and E8. If you do not know what you are looking for, the best thing to do is swim to these locations and discover them first. Make sure your tank is upgraded or you will not have enough air to finish the tasks. You will get three tries before you must leave the area and return later to try again.