Fatal boat collision on Okanagan Lake

CTV is reporting that "Paramedics called West Kelowna RCMP around 11:30 a.m. Thursday to advise them of the collision between two personal watercraft, which had seriously injured one of the vehicles' occupants. RCMP said in a news release that officers responded to the Summerland boat launch, where the uninjured watercraft operator identified themselves as an off-duty RCMP officer. The operator of the other vehicle was taken to hospital, where they died of their injuries.

This is obviously tragic but I'm not sure how this happens. Sunny day, clear visibility - wtf?