Sharrow Marine apparently believes, with good reason, that two are better than one. Its revolutionary no-blade prop represented the first major design change in fixed propellers in a century when it was introduced in 2020. Now, the Michigan company just announced that it will make an upgrade, the CX contra-rotating prop for outboards and sterndrives. The two props will rotate in opposite directions on a single shaft. Sharrow will offer the CX for Volvo Penta DuoProp sterndrives, Mercury V12 outboards, Bravo 3 sterndrives, and Suzuki 300- and 350-hp outboards. The basic Sharrow uses loops to produce thrust, not blades. The…