Help? Where do I find this vending machine?

It's on the Uncharted Island. You'll have to complete an Uncharted Land Map before you can access the island.

You need to complete the Uncharted Landmap in order to get access to Unknown Island. There you'll find the Ocean Depth Vending Machine.

Pieces are the following ^^

[item=Uncharted Land Map Piece ][item=Uncharted Land Map Piece ][item=Uncharted Land Map Piece ] [item=Uncharted Land Map Piece ][item=Uncharted Land Map Piece ][item=Uncharted Land Map Piece ] [item=Uncharted Land Map Piece ][item=Uncharted Land Map Piece ][item=Uncharted Land Map Piece ]

Thank you both :)