Amphibious cycle

An amphibious cycle is a human-powered vehicle capable of operation on both land and water. Some designs allow riding directly into and out of the water, other semi-amphibious cycles must be converted in order to change from one mode to the other.
First designs and patent applications appeared in the late 1860ies for amphibious tricycles using large buoyant wheels and thus able to be driven directly in and out of the water.
In 1895 the German engineer Max Wenkel experimented successfully with water tricycles near Hannover. The two rear wheels were fitted with small paddles for water propulsion.
In 1943 David Vigo, in 1963 Harry Leiberman and in 1971 Ernesto Moraga were awarded US-patents 2,323.261, 3,091,209 and 3,606,856 for their water tricycles. These had been preceded in 1903 by Anton Piller with US patent 728,758 for a similar water quadracycle, and other designs using buoyant ball wheels around since the 1860ies.
A similar two-wheeler, E. Fabri's Cyclomer, was demonstrated in Paris in 1932. As the dynamic stability of a road bicycle does not work on the water, four additional stabilizing ball wheels were fitted that are folded down on the water.
Other semi-amphibious bicycles were constructed using fully roadworthy safety bicycles. The first known such design was developed in 1910 by Baumgartner and Hirth and demonstrated on the Rhine. In water mode three floats are folded down and a propeller drive connected.
In 1915 Julius Bettinger patented and demonstrated a semi-amphibious bicycle on the Neckar using two inflatable floats. It was propelled by paddles connected with levers to the pedals.
Today's designs mostly follow the historic ones. Manufacturers produce models very similar to Morago's "Ciclo Amphibious" of 1971 and earlier designs in large numbers for the waterside rental market, however enlarged to carry two people.
In 1984 Theo Schmidt made the "Amphiped", an inflatable catamaran onto which any standard bicycle could be placed, with a rudder attached to the front wheel and a propeller to the chainwheel. This was used for extended trips along the southern English coast and in competitions.
Very similar is the commercially available Italian Shuttle-Bike Kit. The ensemble, when deflated, fits in a backpack for carrying by the cyclist.
A design which has received much coverage is "Saidullah’s Bicycle." The bike uses four rectangular air filled floats for buoyancy which propelled using two fan blades which were attached to the spokes.
A truly amphibious vehicle is that of seven engineering students at the University of Southampton. The amphibious trike combines a recumbent frame with four separate floats and is propelled using a paddle wheel. A speed test on water achieved an average speed of 1.12 m/s. The cyclist could ride the tricycle in and out of the water without mechanical transition and keep dry even with the bottom third of the wheels submerged.
Another recent design was developed by Ebrahim Hemmatnia for his voyage around the world. This velomobile was called the Melanie.
Competitions for human-powered all-terrain vehicles as kinetic works of art started 1969 in California as the kinetic sculpture race. These often rather large and outrageously decorated vehicles must travel considerable distances on roads including hills, water, mud and sand.