What would be considered a high number of hours on a boat engine? I keep shopping around and see nice boats with 500 hours and I can't help but think that seems 'high'. Comparitevly speaking, when I think of a used vehicle with 50,0000 miles that seems relatively low and I would imagine the engine hours for a vehicle with 50K miles might approach 5,000 hours.

I'm sure someone else can answer this better than I can, but, I would think the life span of a 350 in a car vs. boat would be similar. The only big difference I can see in the same engine is the cooling system for marine engines. Obviously a boat with more hours will have increased wear on seats, hull and all of the other systems in the boat. Fortunately, some people take great care of their boats and high engine hours does not always mean lots of wear and tear.

Is there that much more stress/load on a boat engine compared to a vehicle where I should be concerned about buying a boat with 500-1000 hours on it?