Low tech Amphibious bicycle

The aim of this project is to create an amphibious bicycle from stuff you can find at your local hardware store. I use common tools, so no welding or big machinery. Another goal is that everyone can use his or her own bicycle to make it amphibious. The conversion time, from land to water is not more than 7 minutes; the same for the opposite direction. Beside universal applicable the construction is simple, save and cheap; about 100 dollar.
This project sound's easy; it's not. When it was that simple, we could buy an amphibious bike in the local cycleshop. This video show's enough information to make one for your own. In the water Berto's Amphi-Cycle will be propelled by a new version of the simple outboard motor. With a cordless drill and with an extra 12V battery. I found out that other ways of propelling are too complex and expensive.