A raw caver leads for the first time, rookies attempt to join the Sonoma Marin Tree Men, and a novice flyer travels to Africa to take a rigorous bush pilot course.

A rookie climber ignores advice to scale a redwood, some guys attempt a risky underwater welding job in San Diego, and an amateur pilot goes canyon flying.

Hoping for a job as a commercial diver, Erik welds a patch on a sunken submarine. Plus, a heavy haul driver battles through a hurricane, and a bush pilot is hospitalised.

A rookie diver struggles underwater to rig a sunken yacht; a heavy haul trucker tries to transport a crane through a hurricane; a tree man fells a large, dead Eucalyptus tree.

A rookie tree man freezes in fear on a redwood; a diver collects research samples in the ocean; a volcanologist tries to scale an active volcano.

Volcanologist Sarah continues her first expedition on an active volcano and rookie tree men, Nate and Tomas, have their toughest challenge yet.