• 
  Thom Kikot

   Narrator (10 episodes, 2012-2014)
• 
  Kavan Smith

   Narrator (14 episodes, 2012-2014)
• 
  Nick Eyles

  Self - Geologist
• 
  Greg Hall

  Self - Marine Engineer
• 
  Clayton Alarie

  Self - Excavation Manager
• 
  Silvia La Pergola

  Self - Architectural Engineer
• 
  Vanessa O'Connell

  Self - Hydrographic Surveyor
• 
  Tara Brown

  Self - Geoscientist

• 
  Valerio Foti

  Self - Site Engineer, METRO C
• 
  Philip Holliday

  Self - Harbor Master
• 
  Guido Giordano

  Self - Geologist
• 
  Andy Mackay

  Self - Saltyard Superintendent
• 
  Andrew Marsonet

  Self - Project Director
• 
  Brad Pilans

  Self - Geologist
• 
  Inge Weustink

  Self - Speleologist

• 
  Rob Wilson

  Self - Salt Truck Driver
• 
  John Brown

  Self - Tunnel Engineer
• 
  Helen Cheyne

  Self - Speleologist