Rock guard for trailering?

[bigdog]

Does anyone have any experience with those rock guards to protect whatever you are trailering? I have rubber mudflaps on the truck but they are not stopping rocks from chipping the front of my boat. Have seen the full width rubber and/or brush styles that mount to the hitch mount. Do they work?
Who has them available?

[basguy31]

I looked at one of the full width rock guards which you are refering to. It had the continuous rubber piece which ran accross the entire back of the truck and it mounted to the reciever. It was around $225 or so. I found it at Trucks Unlimited in Big Lake.