Electrolysis-induced corrosion remains this year’s hottest propulsion topic, fueled by a flood of complaints from the owners of decaying MerCruiser Bravo III drives (see April and May editorials).

In light of this, Volvo’s Ocean Series composite sterndrive series couldn’t have hit the market at a better time for the company. We tested one at the Miami Boat Show—a 5.7L OSi-XDP on a Pursuit Denali 2460. A vinylester-based structural composite (woven glass fibers reinforce high-stress areas) completely covers the drive’s aluminum gear housing. The two props are also plastic. …