Most pleasure boats are factory equipped with aluminum propellers. Aluminum props are a great choice for small and medium sized boats. They are inexpensive and under normal conditions can last for many years. When running your boat in an area where striking the bottom is likely, aluminum blades can flex, helping prevent damage to your engine.
Stainless Steel
Stainless steel props are ideal for large or heavy boats and boats running in saltwater. Although more expensive than aluminum, stainless steel props are more durable and will last longer. When running your boat at speeds over 50 mph, stainless props will perform better than aluminum.