【正文】 onsuming to tune the suspension characteristics of thevehicle for land use. For example, users of the vehicle will expect ride fort characteristics on land which are parable to those of a conventional land based motor vehicle.[0005] A further drawback of some known wheel retraction arrangements is the amount of space required to acmodate movement of the suspension means as the wheel moves between its protracted and retracted positions. . Pat. No. 4,958,584, for example, describes an amphibious vehicle having a wheel retraction arrangement in which the wheel is attached to the vehicle body using a wishbone type suspension. A suspension means in the form of a strut having a coil spring located about a telescopic hydraulic damper is connected between an upper Wishbone and part of the wheel retraction system. To move the Wheel to the retracted position, the upper end of the strut is drawn inwardly. This arrangement takes up a considerable amount of space in a central area of the vehicle making it unsuitable for use with a pact amphibious vehicle. The problem is most acute where the engine and transmission are mounted between a pair of retractable road wheels, as there is little space available into which the struts for those wheels can be drawn.SUMMARY OF THE INVENTION[0006] It is an object of the invention to provide an amphibious vehicle having a retractable Wheel arrangement in Which the characteristics of the suspension means can be more easily optimised for road use.[0007] It is a further object of the invention to provide an amphibious vehicle having a retractable wheel arrangement in which less space is required to allow movement of the wheel between its protracted and retracted positions.[0008] It is yet a further object of the invention to provide an amphibious vehicle having a retractable wheel arrangement where the suspension spring does not have to be pressed in order to retract the suspension.[0009] In accordance with the invention, there is provided an amphibious vehicle having a wheel mounted to a body of the vehicle so as to be movable from a protracted position, for use of the vehicle on land, to a retracted position, in which the wheel is stowed for use of the vehicle on water,the vehicle further prising a suspension means to absorb shocks from the wheel during land use and a retraction means for moving the Wheel between the protracted and retracted positions, characterised in that the suspension means can be operatively disconnected from the wheel whenthe wheel is to be retracted.[0010] Because the suspension means can be operatively disconnected from the wheel, the suspension means can be tuned to provide optimum road or land use characteristics without having to promise the design to enable the wheel to be retracted. Furthermore, because the suspensionmeans is disconnected from the wheel, it can remain in its land use position when the wheel is retracted, eliminating the need to allow space to acmodate movement of the suspension means as the wheel is retracted.[0011] Preferably, the retraction means can be operatively disconnected from the wheel when the wheel is in the protracted position.[0012] In a particularly preferred embodiment, the wheel is mounted to the body of the vehicle by means of one or more suspension linkages and the vehicle further prises suspension disconnect apparatus for operatively connecting the suspension means to, or operatively disconnecting the suspension means from, one of the suspension linkages.[0013] Preferably, the suspension means is operatively connected to one end of a suspension lever arm, the other end of the suspension lever arm being operatively connect able to said one of the suspension linkages by the suspension disconnect apparatus.[0014] Preferably, the said one of the suspension linkages and the retraction lever arm are mounted to the vehicle body for pivotal movement relative to the body about an axis and the suspension disconnect apparatus prises means movable between a first position, in which the said one of the suspension linkages and the suspension lever arm are locked so as to pivot together about the axis, and a second position, in which the said one of the suspension linkages and the suspension lever arm are free to pivot about the axis relative to one another.[0015] In one preferred embodiment, the suspension dis connect apparatus prises a bore in the said one of the suspension linkages or in the suspension lever arm, the bore having a number of ball receiving tracks formed over a part of its length, a shaft slidably mounted to the other of the said one of the suspension linkages or the suspension lever arm,the shaft projecting into the bore and having a knuckle about which are mounted a plurality of balls, the shaft being movable from a first position in which the balls are engaged in the tracks to lock the said one of the suspension linkages and the suspension lever arm together for pivotal movement about the axis and a second position in which the balls arenot engaged in the tracks and the said one of the suspension linkages and the other end of the suspension lever arm are free to pivot about the axis relative to one another.[0016] Preferably, the suspension disconnect apparatus prises an actuator, which may be an hydraulic actuator,to move the shaft between the first and second positions.[0017] In an alternative embodiment, the said one of the suspension linkages and the suspension lever arm have adjacent drive portions and the suspension disconnect apparatus further prises a sleeve having drive means for cooperation With corresponding drive means on the driveportions, the sleeve being movable from a first position in which it is in driving cooperation with both of the drive portions to lock the said one of the suspension linkages and the suspension lever arm together for pivotal movement about the axis, and a second position in which it is in driving cooperation w