Why not take a shortcut on tomorrow´s commute and bike across that lake instead of going around?
I found these great photos and story at www.china.org.cn in a post titled, Amphibious bicycle in Wuhan.

This sweet DIY setup was displayed at the Naishahu Park a couple months ago. It is made with eight large 5 gallon water bottles attached to a metal frame connected to the bike. If you check out the wheels in the photos you´ll see they´ve been rigged with paddles allowing it to manuever in the water. Off the water, you can raise the setup so that the water bottles don´t interfere with street riding. This prototype had a budget of 20,000 yuan ($3,000) and there are plans to refine the design and mass produce it.

“Li Weiguo’s daughter Li Jin rides the human-powered amphibious bicycle on the water in Wuhan of Hubei Province, China on May 30, 2009. The amphibious bicycle made by Li Weiguo is equipped with eight water buckets as pontoons and adjustable vane wheels as driving power. This kind of bike can walk on land and on water.