RedactedNarrative: Operator of vessel #1 was traveling at approximately 15 mph on his friends stand up PWC. He took a sharp 90 degree right hand turn. He did not slow or look into his turn. He noticed operator #2 traveling straight towards his bow. He noticed operator #2 turned left in an attempt to avoid collision but was not successful. The bow of vessel #2 hit the starboard bow of vessel #1. The bow of vessel #2 stroke operator #1. Both operator's issued warnings for unsafe operation.