In article , Tim Ingram wrote:
Please See:

http://www.bconnex.net/~timkayak/canoe.html

These are not sponsoons, these are just floating aids. Of the most
stupid and clueless kind, if I may say so.

Real sponsoons are integral part of some types of vessel. Fox example
Joshua Slocum had sponsoons out of bamboo:
http://209.11.144.65/eldritchpress/js/liberdade.htm