Ep 8. Inverted Underwater Car

Inverted Underwater Car is the eighth episode of MythBusters' ninth season, where the show's hosts perform various experiments to test the plausibility of myths and legends.

In this episode, the team tackles the myth of an inverted underwater car. They start the experiment by discovering whether a car can float and remain inverted underwater if it's pushed off a cliff. To test this, they construct a wooden ramp with a hydraulic lift and toss a car into a pool. The conclusion they draw from this test is that the car is likely to flip over, especially in deep waters.

Next, they try to create an underwater ramp to support the car and avoid flipping. They realize it's challenging to build a ramp under the water and decide to use a water jet pack as an alternative. The water jet pack is supposed to keep the car afloat while inverted and propel it forward through the water. After several attempts, the team eventually succeeds in flipping the car underwater, and it doesn't flip back over.

The hosts then test the myth that a car can drive underwater as long as it's inverted. They attach an air tank to the car's cabin and submerge it into the pool. Once the car's wheels are spinning and it's moving forward, water enters the air tank, causing the car to sink.

To overcome this issue, they design a watertight cabin equipped with an air supply. They install a tube to connect the air supply to the cabin while it's underwater. While testing the modified car, they encounter another problem; the car's spinning wheels and direction control don't work underwater. T hey install a jet propulsion system to push the car through the water. The car manages to move forward, and the team concludes that driving a car underwater, even when inverted, is impractical.

Finally, they revisit the myth that a person can escape a sinking car by waiting for it to fill with water and open the door when the pressure equalizes. They construct a scenario that represents a woman and a child trying to escape a car that has fallen into a river. Using an underwater set and dummies, they conduct the test and find that their myth is inaccurate. The team concludes that waiting for the car to fill up and equalize the pressure can lead to drowning, and instead recommends breaking the car window or using an emergency tool to cut the seat belt.

In conclusion, the MythBusters team explores various underwater car myths in the Inverted Underwater Car episode. They test the possibilities of a car remaining upside down underwater, driving the car underwater, and escaping from a sinking car. The team concludes that most of the myths surrounding underwater cars are inaccurate, while some are also impractical.