Propeller Mercruiser. Please choose your type of Mercruiser drive below and you will see all propeller types that fit. See here for an easy 3-step guide for choosing the right propeller. Not sure what is on your boat? Almost all of the Mercruiser inboard engines have the Alpha I drive, take a look there. Please note the pictures of the Mercuiser drives below are just examples, your model can look slightly different.