Most boat owners don't realize they're running the wrong impeller, the wrong anodes, or the wrong oil filter until something breaks. Here's what I see constantly:

1. Impellers — People match by engine brand but ignore the year. A 2005 Yamaha 150 and a 2020 Yamaha 150 take different impellers. Cross-reference the part number, not just the brand.

2. Zinc anodes — Freshwater and saltwater require different alloys. Zinc for saltwater, magnesium for freshwater, aluminum for brackish. Wrong choice = zero corrosion protection.

3. Oil filters — "Universal marine" filters are never universal. Your engine's bypass pressure matters. Wrong filter = unfiltered oil circulating at high RPM.

4. Fuel/water separators — The micron rating matters more than the brand. 10-micron for primary, 2-micron for secondary. Most people run the wrong combo.

5. Trim/tilt fluid — ATF is NOT the same as marine hydraulic fluid. Using the wrong one slowly destroys your seals.

I built BoaterBud to solve exactly this — punch in your boat's make and model, get the exact parts that actually fit. No more guessing at the parts counter.