the other day while running across bull shoals lake in north Arkansas, i sheared one of my prop blades off. i was running in the river channel in open water. i didn't hit anything. my motor was vibrating really bad afterwards. i drove the boat for about 20 minutes back to the launch. i drove just fast enough to keep the boat on plane with the motor trimmed out as far as possible. the vibration was barely noticeable with the motor trimmed out. i pulled off the prop and checked the seal and also eyeballed the shaft. everything appears to be ok. should i be concerned with internal damage? what should i check for?