Walter Höhn (English Hoehn) had built, developed and then tested his design for a folding kayak in the white-water rivers of Switzerland from 1924 to 1927. In 1928, on emigrating to Australia, he brought 2 of them with him, lodged a patent for the design and proceeded to manufacture them. In 1942 the Australian Director of Military operations approached him to develop them for Military use. Orders were placed and eventually a total of 1024, notably the MKII & MKIII models, were produced by him and another enterprise, based on his 1942 patent (No. 117779)
One of the most common uses of kayaks for hobbyists is whitewater kayaking. Whitewater kayaking is when a kayaker traverses down a series of rapids. The difficulty of these rapid ranges from Class I to Class VI. The difficulty of rapids often changes with water level and debris in the river. Debris that inhibits a kayakers path are often called "strainers" as they "strain" out the kayakers like a colander. There are often training camps as well as man-made structures to help train kayakers.
Kayaking is the use of a kayak for moving across water. It is distinguished from canoeing by the sitting position of the paddler and the number of blades on the paddle. A kayak is a low-to-the-water, canoe-like boat in which the paddler sits facing forward, legs in front, using a double-bladed paddle to pull front-to-back on one side and then the other in rotation. Most kayaks have closed decks, although sit-on-top and inflatable kayaks are growing in popularity as well.