The act or art of biffing it while doing any kind of thrillsport. IE, motocross, snowboarding, wakeboarding, rock climbing. Etc. In most cases, the wreck is so significant, that a string of gear is slung in and or around the impact area simulating what is typically know as a (Yard Sale). However taking into consideration, that one is typically (sailing) prior to this now recognized art of the dynamic crash, the word YardSail was born.... Note- not to be confused with a Yard Sale.
Damn bro, it appears as though we have a slew of squids and rookies out here today. SURELY we will see some massive YardSails throughout the day.