How can you get the white daulphin in endless ocean

The " white dolphin" is really a baluga whale. To get the White Dolphin email you need to translate all six of the stone tablets in the ruins. In order to that you must find all four parts of the Nephrite Inscription and return to the boat. Then you can go back to the ruins revisit the tablets. Then you will get the White Dolphin email. Now you can get the bracelet from the Gallery of Souls. When you return to the ruins you will find the beluga whale in the little room with the high door of another room (it contained one of the tablets). BTW - you can get the beluga to become you partner too. Hope this Helps!