Continuous duty version is 1800 rpm, I think, maybe 500 hp at that rpm. 700 hp at 2100 is the sport boat version. Medium rating is 600 hp at 2100. I know of a 600 hp w/ over 30,000 hours. Wet liners, so a bad heat exchanger can really fuck one up if saltwater gets in the coolant. Jacket water aftercooled. Smoky, but legendary in endurance. It's a Komatsu, so no marine parts can be gotten w/o paying the Lugger mark-up. Individual cylinder heads if you need to pull one, or put a kit in. I think suggested maintenance on injection pump and nozzles is (Denso) is every 2000 hours. Different tips to injectors f/ 600 or 700 hp version. It's a scarce engine in the grand scheme of things and no longer available new b/c of emissions.