The Wandering MC is a prepper and delivery recipient of Sam's. When Sam connected with him the prepper gave him the Sea Otter Suit, which enable Sam to swim easily in the river and won't be drifted away. Like the other preppers his terminal is integrated into the Chiral Network.

Preppers are characters who live, alone or with their families, in isolated bunkers across the continental United Cities whom Sam can make deliveries to. They will appear holographically at their delivery terminals to converse with Sam, but will typically not physically come above ground. If Sam takes too long to deliver or delivers damaged goods to a prepper, he will receive fewer likes from them for the delivery. Should Sam make more deliveries to a prepper and become more acquainted with them, they may join the Chiral Network and afterwards give him more items.

If a prepper is not willing to join the Chiral Network, Sam may negotiate with them. After a prepper terminal is connected to the Chiral Network, Sam can use the terminal to organize and print items.

Source: https://deathstranding.fandom.com/wiki/Prepper