There is NO multiplayer, it is possible to activate a button and menugroup for that, but it doesn't work at all.
You can do nothing (well, at least nothing the other one you're playing with can see) not eat, not use items etc, you can't even write messages to each other.
For those who want to know it anyway:
open the folder:
mods Stranded II sys
and open the game.inf . Search the entry menu_multiplayer=0 and switch it to 1. After that just start the game.
DC is NOT (never ever) going to implement a multiplayer feature.
It's not possible to implement MP in a Mod, too. For that, you need the source code of Stranded 2 (yes, it is open source). You also need an expensive compiler, and very good abilitys in "Blitz3D", too.
I hope that was clear and there wont be so much questions about multiplayer, in the future. Please don't open threads concearning this one, I don't want people to hope to much for a MP mode.
sincerly