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Amphibious Encyclopedia · Tours and transport

Hydra-Terra

The Hydra-Terra is an amphibious tour bus built by Cool Amphibious Manufacturers International (CAMI) of Bluffton, South Carolina. It carries 30 to 49 passengers plus two crew and has foam-filled compartments that, according to its maker, keep it afloat at full load even when the hull is flooded [1][2]. Tour operators have used it as a purpose-built alternative to converted World War II DUKWs [5][6].

  • Tours and transport
  • 2000s to present
  • United States

Maker and origins

The Hydra-Terra was designed by John Giljam, the founder of CAMI. Giljam had rented personal watercraft at a resort near Hilton Head Island, South Carolina, and used an old military amphibious vehicle to launch them. Finding that rides on the amphibian earned more than the rentals, he turned to building amphibious tour vehicles [3]. CAMI dates its founding to March 31, 1999 [2].

The company also builds the Terra Wind amphibious motor coach and the Hydra Spyder amphibious car [2]. In 2014 Good News Network reported that CAMI had built 75 Hydra-Terras, in use in 17 countries [4]. CAMI's own Hydra-Terra page now says the bus has operated in 27 countries [1]. A 2006 CAMI press release described one example built for Wonder Bus Tours in Dubai [8].

Design

The Hydra-Terra looks like a tour bus built on top of a boat hull. Its main safety feature is urethane flotation foam installed below deck, which CAMI says is approved by the US Coast Guard and covered by its patent [2]. The engine room and passenger area are separated, and the bus has higher sides above the waterline than the DUKW it is meant to replace [5]. CAMI says it tested the design with the drain plugs removed, the hull and engine room flooded and barrels of water aboard to match a full load, and that the bus stayed afloat [2].

On land, power goes to all four wheels. A 2021 report described a 7.2-liter Caterpillar C7 turbodiesel rated at 300 hp (224 kW), while a 2006 release listed a 210 hp Caterpillar 3126 [5][8]. In the water, a ZF marine transmission turns a 26-inch (66 cm) bronze propeller on a stainless steel shaft, and an electric actuator moves the rudder [2]. CAMI offers 30 ft and 40 ft (9.15 m and 12.2 m) versions, a jet drive as an option, and says it can fit other engines so that buyers can get local service [1][2].

CAMI describes the Hydra-Terra as a fully inspected US Coast Guard passenger vessel for domestic use, having passed hull, welding, electrical, stability and sea trial checks before receiving a certificate of inspection [2]. These are the maker's statements.

In service

Duck tour operators have used the Hydra-Terra on river and lake routes. In Texas, Austin Duck Adventures ran its 75-minute tours of downtown Austin and Lake Austin in Coast Guard-inspected Hydra-Terras [7]. After the 2018 sinking of the DUKW Stretch Duck 7 on Table Rock Lake, a new company, Branson Duck Tours, announced plans to run tours there with CAMI-built Hydra-Terras carrying 40 passengers, citing their foam-filled buoyancy. The plans were reported in January 2021 [5][6].

Sources

  1. State-of-the-Art Hydra-Terra, Cool Amphibious Manufacturers International (CAMI). camillc.com/hydra-terra
  2. CAMI's Catalog: 26th Anniversary, Cool Amphibious Manufacturers International (CAMI) (2025). camillc.com/wp-content/uploads/2026/01/2025-CAMIs-Catalog-Updated-121225-18ccc556-d6d3-4f21-934f-c14c86cc97e5.pdf
  3. The Terra Wind: An Amphibious RV!, Core77 (2014-06-23). www.core77.com/posts/27201/the-terra-wind-an-amphibious-rv-27201
  4. Self-Taught Man Builds Amphibious Motor Home Able to Drive Into Lakes (WATCH), Good News Network (2014-11-07). www.goodnewsnetwork.org/self-taught-man-builds-amphibious-motor-home-able-drive-lakes-watch
  5. America's Aging, Dangerous Duck Tour Boats Could Get Replaced With This Amphibious Truck, The Drive (2021-01-11). www.thedrive.com/news/38653/americas-aging-dangerous-duck-tour-boats-could-get-replaced-with-this-amphibious-truck
  6. With New Vessel and New Operator, Missouri Duck Boat Rides Resume, The Maritime Executive (2021-01-10). maritime-executive.com/article/with-new-vessel-and-new-operator-missouri-duck-boat-rides-resume
  7. Austin Duck Adventures, Time Out (2017-08-30). www.timeout.com/austin/things-to-do/austin-duck-adventures
  8. 2006 C.A.M.I. Hydra Terra, Serious Wheels (reproducing a CAMI press release). seriouswheels.com/2006-cami-hydra-terra.htm

Last reviewed November 2026. Spotted something to correct or add? Tell us and include a source.

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WaterCar has designed and built amphibious vehicles in Southern California for more than 25 years. We keep this encyclopedia so anyone curious about vehicles that cross between land and water has one place to start, with the sources listed for every fact.

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