Most pleasure boats are factory equipped with aluminum propellers. A good quality aluminum propeller will provide satisfactory performance for most family and fishing boats. Aluminum propellers are relatively inexpensive, easy to repair, and under normal conditions can last for many years. If you are happy with the performance of your prop, and it is in good condition there is no need to change it. If you are looking for better performance than can be provided by your aluminum propeller, such as ultimate top speed or better acceleration, a stainless steel propeller will probably be required.
Stainless steel is much stronger than aluminum, and can consequently withstand far more abuse.
The 3 blade prop has been the design of choice for performance boaters for many years. It works well, provides good acceleration and control and excellent top speed performance. The 4 blade configuration is popular with boaters who are looking for a great hole shot, good acceleration, and strong, predictable low to mid range handling, at a possible expense of top speed. This group of boaters includes certain types of fishing boats, ski boats, and boats that are used in rough water conditions. This is due to the fact that 4 blade propeller has slightly more drag in the water.