Ford GPA The Ford GPA ' Seep ' ( from Seagoing Jeep ) , was an amphibious version of the WWII Ford GPW Jeep . Unlike the jeep , the seep was not a successful design being too slow and heavy on land and lacking sufficient seagoing abilities in open water . Similar design features were used in the larger and more successful DUKW amphibious truck . History and development . After having commissioned Willys , Ford and Bantam to build the first 4 , 500 jeeps ( 1500 each ) in March 1941 , the US Motor Transport Board set up a project under the direction of the National Defense Research Committee ( NDRC ) to be designated " QMC - 4 1 / 4 Ton Truck Light Amphibian " . As the war in Europe progressed bridges were frequently destroyed in front of the advancing Allies and the requirement for an amphibious version of the jeep arose . Roderick Stephens Jr . of Sparkman & Stephens Inc . yacht designers was asked to design a shape for a 2700 lb ( 1 , 200 kg ) amphibious jeep , in the same vein as his design for the DUKW six - wheel - drive amphibious truck . Not surprisingly Stephens ' hull design looked like a miniature version of that of the DUKW , and just like it , the ' Seep ' was going to have a screw propellor , driven by a power take - off , operating in a dedicated tunnel faired into the rear end bodywork , as well as a proper rudder . The construction of the vehicle was developed in competition by Marmon - Herrington and Ford Motor Company . Marmon - Herrington specialised in all - wheel drive vehicles . The Marmon - Herrington prototype ' s hull formed an integral unibody structure , created by cutting shapes out of steel plate and welding those together , much like the hull or chassis of an armoured vehicle . The Ford entry however used a sturdy chassis and internal frame , to which more or less regular automobile type sheet - steel was welded . This construction made the GPA some 400 lb ( 180 kg ) lighter than its competitor . Also The GPA ' s design was based on the Willys MB and Ford GPW standard Jeeps as much as possible . When designing and building the GPA , Ford utilized many of exactly the same parts that the Ford GPW did . The GPA had an interior similar to that of the MB / GPW jeeps , although the driver ' s compartment had almost twice as many control levers : 2WD / 4WD , hi - range / lo - range , capstan winch ( on the bows ) , propeller deployment and rudder control . After a direct comparison of the two company ' s prototypes , Ford received a contract for production starting in 1942 . Service . In contrast to the DUKW the GPA ( G = Government , P = 80 " wheelbase , A = Amphibious ) did not perform well in the field . At some 1 , 600 kg ( 3 , 520 lbs ) the production craft had become much heavier than the original 1 , 200 kg ( 2 , 640 lbs ) specified in the design brief , but its volume had not been increased accordingly . As a consequence a low freeboard in the water meant that the Seep couldn ' t handle more than a light chop , and certainly couldn ' t take much cargo . The Seep ' s intended objective : to ferry soldiers to and from ships off - shore , to trundle up the beach and continue inland , was therefore not met . It is reported that many of the Jeeps that were used in battle sank if there were any significant waves at all . On land the vehicle was too heavy and its body too unwieldy to be popular with the soldiers . Adding insult to injury , the GPA would frequently get stuck in shallow waters , where the regular Willys MB ' s water fording abilities allowed it to drive straight through ( Pohl , 1998 ) . Production was already halted in March 1943 after production of only 12 , 778 vehicles , due to financial quibbles between Ford and the US government , as well as bad reception of the vehicle in theatre . Although some sources ( Pohl ; Carlin , 1989 ) state that less than half of that number were ever completed , serial numbers of surviving specimens suggest that the 12 , 7XX figure is actually correct . In spite of participating successfully in the Sicily landings of September 1943 , and performing reasonably well in inland river crossings , most GPA ’ s were routed to Russia under the Lend - Lease program . GPAs were also used in action North Africa , Normandy France , Holland and the South Pacific . They were also used by the British , Canadians and Free French / Fighting French . Postwar . The Russians were sufficiently pleased with the GPA ' s ability to cross rivers and inland waters to keep developing it after the war . Starting out with the chassis of the GAZ - 67 B , prototypes were created that largely copied the Seep ' s layout and design , eventually leading to the GAZ 46 MAV , based on the chassis and mechanicals of the GAZ 69 4×4 jeep , to go into production as of 1952 . Both the GAZ 69 and the amphibious GAZ 46 were exported to many communist countries . By 1944 GPAs were being sold as surplus and were purchased by farmers , ranchers , adventurers and others . By the 1970s collectors had discovered them and started restoring them back to their original specifications . They appear at various military vehicle shows and the Normandy " D - Day " anniversaries in June . Half - Safe and other conversions . After World War II , several adventurers converted surplus GPAs into world - travelling machines . The most famous one was during the 1950s when Australian Ben Carlin ( 1912 – 1981 ) sailed and drove a modified Seep , that he called " Half - Safe " on a journey around the world . A young American couple converted one which they called " Tortuga " and travelled from Alaska to the Southern tip of South America . They later converted another one which they called " Tortuga II " which they used in the South Pacific . A World War II British paratrooper veteran named Lionel Force purchased a GPA from Levy ' s Surplus in Toronto , Ontario , Canada , and called it " The Amphib . " Among the many changes he grafted on a roof from a Dodge station wagon and lengthened the hull at the stern . He used the top halves of the doors , but knowing that he might be tied up alongside a dock , he added a round roof hatch on the top . He planned to travel from Toronto to England via the USA , Mexico , Guatemala , Panama , South Armerica including Brazil , Africa , the Middle East , Greece and up to England . He got as far as Panama but turned back when he learned that the freighter upon which he intended to ship " The Amphib " from Brazil to Africa had been taken out of service . Indiana Jones . Replicas of the GPA are featured in the 2007 Film " Indiana Jones and the Kingdom of the Crystal Skull " . Custom built by Ghostlight Industries of San Fernando , California , the fiberglass bodies were intentionally constructed 10 % larger than the actual vehicle to ease filming .