RedactedNarrative: O1 and P1 were cruising on Cottonwood lake at approximately 5:00pm. O1 was traveling at approximately 20 to 25 mph. O1 was unaware of any boating hazards and said depth was approximately 5ft. O1 hit a large submerged rock, causing extensive damage to V1. Lower unit is a total loss and a V1 has a large hole on the bottom. No one was injured.