Final answer:
The incorrect characteristic of a wet sluff avalanche is that it is typically triggered by skiers or snowboarders; these avalanches are usually caused by natural conditions like rapid snowmelt.
Step-by-step explanation:
The characteristic of a wet sluff avalanche that is NOT accurate is that it is typically triggered by skiers or snowboarders. Wet sluff avalanches occur in wet snow conditions, are indeed a type of loose snow avalanche, and are characterized by being slow-moving with a high water content. However, although skiers or snowboarders can sometimes trigger loose snow avalanches, wet sluff avalanches are more frequently the result of natural conditions such as rapid snowmelt or rain on snow events. These avalanches occur when the cohesion between snow grains is reduced due to the presence of liquid water, which eventually leads to a release.