I wasn't riding on this occasion (sigh) but several years ago I was driving on family vacation in British Columbia's lake country and was following three riders. Was giving them lots of room which proved to be a wise choice. These motorcyclists were following a pickup truck that had a rubber raft tied down in the bed -- or so the driver thought. The thing broke loose and sailed into the air and landed in front of the riders in the middle of a rural two lane highway. They all managed to avoid it without going down. It was close. Whenever I see a large object like an inner tube or raft tied down in a pickup I move past faaast.