Prop Strike: What to Do After Hitting a Rock

Free Nav Rules Course - https://www.nauticed.org/powerboating-courses/view/navigation-rules-for-powerboats?utm_source=youtube&utm_medium=video&utm_campaign=lSg1tKSKTEk New England Propeller - https://neprop.com Prop strike after hitting a rock or the bottom? This guide explains why you should NOT DIY a prop repair and what to do next. The damage you can’t see—pitch shift, blade alignment, balance/runout—can quickly lead to vibration, lower-unit wear (outboard/sterndrive), or cutlass-bearing damage (inboard). Home tools can’t measure pitch/balance accurately; a professional prop shop uses pitch blocks, runout gauges, and balancing equipment and provides before/after reports so you know it’s right. What we cover: - Don’t DIY: Grinding material off a blade makes imbalance and weakens the prop - Hidden damage: Pitch moved, blade alignment off, hub issues—even if it looks “okay” Inspect after a strike: - Outboard/IO: prop, edges, hub, lower unit (leaks, noise, metal in oil) - Inboard: prop, shaft, strut, rudder, cutlass bearing (play/heat) - Aluminum vs stainless: Aluminum with big metal missing is often not cost-effective to repair Stainless is pricier and more repairable—worth professional work - Twin props: If one looks bent, “just check” the other—often both need work - Fix it promptly: Running with vibration accelerates wear and raises costs - What a shop does: Measure pitch, correct alignment, true & balance; provide pre/post reports Quick After-Strike Checklist: Stop DIY ideas—no hammers, torches, or grinding Visual check: nicks, bends, cracks, missing edge, cup/rake distortion Spin test: obvious wobble/runout at blade tips Lower unit / seal check (OB/IO): new drips, milky/metallic oil, noise Inboard gear: shaft straightness, strut alignment, cutlass bearing play Bring it in: ask the prop shop for measurement + balance and a report FAQ Can I repair a bent boat prop at home? No. Without pitch blocks and balancing, you risk worse vibration and drivetrain damage. How do I know if my prop is too damaged to fix? Large metal loss on aluminum is often a replace call. Stainless can usually be repaired by a shop. What symptoms show hidden prop/shaft damage? New vibration bands, loss of WOT RPM, leaks at seals, heat at cutlass bearing, metal in gear oil. Why fix it quickly after a prop strike? Running out of balance stresses the lower unit, bearings, seals, and mounts, increasing repair costs. 00:00 - Intro 00:16 - Fixing it Yourself 00:39 - Vibration Wear 00:57 - After Strike Checklist 01:10 - How Damaged is To Damaged 01:33 - Damage You Can't See 02:09 - Outro #powerboat #boating #boat