D&D 5E Zombies: Sink or Swim?

[Voadam]

They build a raft.. out of other zombies!

There is a precedent for using buoyant dead bodies as part of a raft.

Tales of the Black Freighter

 

[Mad_Jack]

Zombies ain't nowhere near that smart or co-ordinated.

And yet all the ones I work with are somehow shambling around looking at their smartphones without running into the walls...

They build a raft.. out of other zombies!

Reaper Miniatures' Raft of the Damned is built on the back of a zombie shark, which means it's self-powered...

 

[Voadam]

Reaper Miniatures' Raft of the Damned is built on the back of a zombie shark, which means it's self-powered...

I can picture a necromancer making a zombie raft and then commanding the zombies to flutter kick in the same direction as a slow motor. The zombie shark motor would work even better.