Expensive Day

Earlier in the year we moored up next to a fellow yachty. He said if I were you I'd check your exhaust elbow, that's what may be causing the black marks near your exhaust outlet. I thought I'll check that when I layup at the end of the year, however things took a turn when engine suddenly lost power.
Turns out both elbow and manifold totally blocked. Big bill! Wise man that yachty.