It's a car! It's a boat! It's neither! "Wake" up and jet into the wild world of amphibious vehicles with 20 awesome one-if-by-land two-if-by-sea gear shifts.
Amphicar

German engineering continued to soar in post World War II vehicles, but no one expected amphibious to be the buzz word of the luxury car game until 1959. Hans Trippel joined the Bugatti company in France after working through the war crafting amphibious vehicles for the Wehrmacht, and produced this stunning and yet normal looking vehicle that sold for a pretty sum of $3,000 in 1961.
Gibbs Aquada

Gibbs brought a 175 horsepower sports car to the water in 2003 as their first production model after 7 years of aquatic research. Using a jet system after making a seamless transition from land to sea, the Aquada produces over 1 ton of thrust when in water, allowing it to travel over 50 kph.
VW Schwimmwagen

The Germans broadened the scope of all terrain vehicles during the second World War when VW mass produced the "Schwimmwagen" for use by German infantry. Based off the body of the original Volkswagen Beetle, over 15,000 propeller powered vehicles were produced. The vehicle mustered a meager 25 hp in water, making for a canoe trip of a river crossing for many German sitting ducks.
US Army “Duck” DUKW

American engineers fought back their German counterparts with a 6 wheeled, 2 ton amphibious truck designed to carry troops and supplies over land and water as well as orchestrating beach heads. Although their designs were only meant to last through combat, many Ducks were later repurposed as tourist vessels in marine environments.
Terra Wind Motorhome

Anyone at the helm of this luxury vehicle can shock anybody anywhere if a body of water is present. For a cool $1.2 million, you can roll of the highway going 80mph and take a river cruise at up to 7 knots, all while looking like a very forgetful ship captain.
Dobbertin Surface Orbiter

Starting in 1995, Rick Dobbertin turned a double walled milk tank into a six wheeled amphibious beast in just four years time. Weighing 9 tons when fully loaded, it's diesel V8 drove 350 horsepower over 3,000 miles in the sea and 33,000 miles on land. He famously drove the truck from Florida to South America via the Gulf of Mexico before he had to sell it off in a 1999 divorce auction for $200,000.
Rinspeed Splash

The light and nimble Rinspeed Splash was a concept to prototype 825kg amphibious car capable of 0-100km speeds in just 5.9 seconds when waterborne. Jetted by a 750cc two cylinder turbo charged engine, the car sits atop a hydrofoil apparatus that lifts the bulk of the vehicle out of the water to reduce drag. In 2006, it set the record for the crossing of the English Channel in just 3 hours and 14 minutes time.
Sea Roader

Mike Ryan of England built this Land Rover bodied amphibious vehicle back in the 1980s. With two separate engines, the steel paneled car-boat totes two separate engines: a 1.7 liter turbo diesel for the road, and a separate marine engine and jet that is capable of pushing the car up to 6mph in the water.
US Army LARC

The US Army built the welded steel 60 ton LARC–Lighter, Amphibious Resupply, Cargo–to handle a whole heap of things in its supply bed. With room for 200 people, the LARC could also carry up to 100 tons of cargo and was powered by four 265 horsepower diesel engines positioned in the sides of the hull, each of which in drove one of its four wheels. With a top speed of 7.5 mph afloat, the incredibly inefficient vehicle still did a lot of heavy lifting during WWII.
Dutton Commander

Tim Dutton is one of the world's most renowned amphibious car kit makers. He is so highly revered by his staff that his production model Dutton Commander was adopted as a testament to the quality of workmanship he puts into his builds. The vehicle proved its worth when one was able to cross the English Channel in force 4 winds.
Watercar Python

What happens when you take a turbo charged Corvette engine and slap a jet drive onto it? Well, Watercar would be happy to tell you that you now officially own their amphicar. Weighing in at almost 2 tons and hitting speeds of 60mph when waterborne, the Corvette smacked into a ridiculously short F-150 body kit must cut down on the turbocharge while on land. When hitting the road, the 640hp Python's speed tops out at 100mph.
Watercar Camaro

The fiberglass body of Watercar's first production vehicle resembles the 2002 convertible Camaro, but with a beefy 300 horsepower engine siphoned into a Berkeley Jet Drive, the amphibious cruiser tops waterborne speeds of up to 40 mph. Roll out of the water and onto the road, and the wheeled roadster hits a modest 125mph.
Watercar Panther

The tagline "It's a Jeep Thing" was officially remastered in 2013. Equipped with a rugged off road Jeep CJ-8 suspension and rigged with a Honda Acura 3.7-liter V6, this 305 horsepower candy colored ride is capable of speeds of up to 44mph in the water and 80mph on the road.
Conte Schwimmwagen

Herzog Conte took after the ugly design trend of late 70's station wagons when he built the world's first amphibious SUV in 1979. The production model car weighed in at 5,100 pounds was powered by a 135 horsepower engine that could switch from powering wheels to propeller with a simple gear shift.
Rinspeed Squba

Built literally around a Lotus Elise, the famous James Bond car advanced from dream to concept at the 2008 Geneva Motor Show 30 years after its film inspiration. The design revealed an open convertible design and rotor driven thrust to propel its drivers through shallow depths underwater.
Amphicoach

2009 brought the world's first fully amphibious passenger coach to the market. Perhaps in an effort to modernize Venice, Italy's public transportation system, Amphicoach boasts a pretty bus-ly looking Italian chassis from Irisbus. So far the sea and land-ready hull has gathered double digit orders.
Lamborghini Countach

Mike Ryan's most expensive and renowned amphibious invention/conversion is his Lamborghini Countach. He added the vehicle to his Sea Roader fleet in 2009, when he essentially added a jet propulsion system and hull to his otherwise freakishly expensive car.
Gibbs Quadski

The "A" in ATV can officially now also stand for amphibious. The popular Gibbs amphibious vehicle line introduced its Quadski that coupled its high speed amphibious HSA technology debuted with the Aquada with the much more versatile build of an ATV. Able to convert from land to seaborne in 5 seconds, a single button press brings a maximum land speed of 45mph to an equivalent 45mph by water.
Jeep Unlimited Lifeguard

Geeho Cha essentially reinvented the wheel when he entered this design to the Michelin Design challenge in 2012. Calling it the Amphibious Hoff Roader, the officially dubbed Jeep Unlimited 2046 design is meant to cater to a future lifeguard's needs. Inspired by the popular TV show Baywatch, Cha developed an off road design that could be pared down in size and adapted utility for a lifeguard demanding speed and control.
Dubai 2030 Amphi X

Designed as a concept for production around 2030, the project Amphi X was inspired by the guys at Top Gear who had taken interest in the development of amphibious vehicles. The Amphi-X focuses on a vehicle that does not boast a large hull underneath its body or a clumsy propeller system, and instead opts for sleek detailing and dual water/land traction systems for total control.