S1, E6: Longtime friends screech down a record-breaking roller coaster in Ohio, while surfing buddies plunge off the top of the food chain in South Africa; riders thunder down New Zealand's longest river.

S1, E6: Longtime friends screech down a record-breaking roller coaster in Ohio, while surfing buddies plunge off the top of the food chain in South Africa; riders thunder down New Zealand's longest river.