To find and acquire the miltos shipment in Red in the Wreckage on Lestris in Assassin’s Creed Odyssey dive down the the sunken ship and open the four chests in the wreckage.
All Keos Guides
All Assassin’s Creed Odyssey Guides
Swim up towards the shore and open the chest on the cliff.
Get out of the sea and onto the beach and open the chest there.
Next: Investigate the Graffiti