Hey guys. It doesn't seem the marine section gets many looks, and these 5.9 hpcr engines (qsb 425's)are pretty simliar to the engine I have in my Dodge. I just picked up a boat over the winter that has twin cummins 5.9's rated at 425hp. They have 3.5gals of oil capacity and the boat stays in the water all season. A typical season here on lake erie is 5-6 months and a few hundred engine hours. Considering the cost of the boat, or even one 350gallon fill up of fuel, I do not care about the cost of the oil, I want to use the absolute best oil for the application in terms of protection, resistance to oxidation, etc. Recommendations?