The Deepback Bay is a location found in Breath of the Wild.
The bay is situated in the southeast corner of the map, southeast of the Hateno Ancient Tech Lab. Along with the nearby Hateno Bay, Kitano Bay, and Loshlo Harbor, the Deepback Bay is part of the great Necluda Sea. The area is rather quite, as while there are Blue Lizalfos and Water Octoroks, they are few and far between. On the east side of the bay there are several Ore Deposits and even a Rare Ore Deposit.
On the west side of the Bay there is a Raft located by the pier that sticks out into the bay. Just north and east of the pier, there is a treasure chest underwater that can be pulled up using Magnesis. There is an Opal gem found inside.
At the far north end of the bay, there is a small cave that has two statues with offering plates. One of them has a Palm Fruit in it. Place a palm fruit in the other offering plate to get the Korok Seed.
Nearby Korok Seeds
Place a palm fruit in the empty basket. If you need one, they are growing at the top of palm trees to the south.