The phone number for Mercury Propeller Warranty is 405 743 6539. The address for returning props to Mercury is;
W6250-22B Pioneer Road
Fond du Lac, WI 54935
Unfortunatley blade failure is a part of high performance boating. Engine horsepower has exceeded the original design limitations of the Bravo style prop. Not so long ago 330hp was a big deal and the Bravo drive held up well. Now it's routine to have 800-1000 hp put through a Bravo drive. Both the drive and the prop are stressed to the max.
We have found that the 5 and 6 blade props hold up better than the 4 blade props. The failure rate of the 6 blade props is extremely low. The load is distributed amoung more blade are thus reducing the load on any one blade. The drive also has less stress due to a substantial decrease in vibration, especially in applications with high drive heights.
There are also some boats that are much more prone to blade failure than other due to hull design.