The different barrel length options for the Lab Finished Maximus LT and ST propellers have been a used for years to fine tune stern lift on boats powered by twin sterndrive engine.

A long propeller barrel can negatively impact top-speed performance in many fast boat applications when stern lift created by the barrel causes the boat to run too flat. The Mercury Racing Bravo I FS, Bravo I XS, Bravo I OC, MAX5, MAX5 ST, and Maximus ST all feature shortened and tuned barrels to dial back stern lift. The Bravo I OC and MAX5 ST represent the most extreme versions of this treatment, featuring very short barrels that perform especially well when an ultra-lightweight boat is paired with high-horsepower outboard power.

If you are up to speed on our previous Prop School Blogs, you will know that the barrel is not the only part of the propeller that provides lift. But if a propeller is generating too much lift due to diameter or blade count, the barrel is often the first part of the propeller to “hit the chopping block.”

The MAX5 ST is suitable for lightweight bass boats and catamarans featuring the 250R, 300R, and 450R outboards.

The Bravo I OC is specifically designed for twin engine two stroke powered catamarans.