PowerTech OFS 15-1/4 x 14 prop & Permatrim M9 hydrofoil ? Thanks Da Nag for your write-up on the Permatrim unit. Performance (cruise weight, sea level & flat water) - WOT = 31.4 Kn SOW @ 5,750 RPM. Negligible vibration during low speed operation, smooth~easy transition to planing speeds, and excellent tracking.