How An Electric Toyota Land Cruiser Was Able To Drive 4 Miles Submerged Underwater

You may have seen a German man named Otto driving his tiny, red Fiat across the ocean just to take it to a Meineke Car Care Center in America. That comically fake commercial notwithstanding, a group of Australians recently did drive a real-life electric Toyota Land Cruiser underwater. While its trip wasn't nearly as long as Otto's, it still broke a world record.

On July 29, a team of electrical engineers and commercial divers drove a 1978 Land Cruiser nicknamed the "Mudcrab" from Mindil Beach to Mandorah. It's a distance of about 4.3 miles at depths reaching 100 feet. Aside from being a busy shipping channel, the harbor is home to an array of tiger sharks, saltwater crocodiles, and, yes, actual mud crabs.

The trip across the harbor was only supposed to take about seven hours, but the team ran into problems. Each tire was filled with 330 pounds of water to keep the vehicle submerged, but the added weight caused the Land Cruiser to get stuck at several points. The team used buoys to get it unstuck.

And if the persistent muck wasn't trouble enough, a gas pipeline forced an extra two-hour delay. Ultimately, it took them almost twelve hours to drive the full distance underwater.

The story of the "Mudcrab" starts back in 1983. Tim Proctor tried driving across the same harbor using the same Land Cruiser. During that attempt, the Toyota was still a combustion engine fitted with a nearly 200-foot-long exhaust pipe snorkel. That journey ended some 1.8 miles in when some of the engine's special seals failed, and the team encountered a rock ledge that stopped them in their tracks.

Joined by Proctor's oldest son, Tom, the modern team spent a year planning and six months working on the Land Cruiser to convert it from a gas guzzler to an electric vehicle powered by a 32 kWh battery, complete with an oil compensation system and a waterproof engine. The transmission and differentials could handle the water and thus didn't need "waterproofing," but the electric motor — a NetGain HyPer 9 – did. They accomplished this by dropping it into a trash can full of silicon oil. The powertrain provided 162 lb-ft of instant torque but still wasn't enough power to get it through some of the mud.

The pressure from the water at almost 100 feet required that drivers change out every 15 minutes, thus requiring such a large team effort. And they didn't use tanks. Instead, an air hose ran from a support boat on the surface, providing a constant supply of air, power and data cables for the cameras and lights, and some extra help navigating through the poor visibility.