Hi Paul: I was one of the authors of the article on Wet Exhaust posted on the Sentoa website several years ago. The basic information is still valid. Our 6BT5.9 had a design error that may (or may not) have been corrected by the time yours was built. A couple of things. . SS Wet Exhaust nozzle assemblies tend to last around 10-years or maybe 1,500 hours. . The FRP exhaust pipe running through the salon does not do well with temps over about 150F. 1. At the time ours was built, a design error directed National Marine Exhaust in Marysville to provide equal sized water spray holes around the exterior of the housing. I visited Cummins and found that the original design called for smaller holes at the bottom and larger at the top, allowing better distribution at lower volume flows at lesser cruising speeds (1,400 rpm or so). This led to a lot of exhaust gasses not seeing any water spray at all. Turbo exit temp went straight down to the FRP ! 2. We had one other detail that contributed to the problem. The original Cummins exit nozzle from the heat exchanger faced aft in the original engine design. NT just plumbed it up, forward again, and then up again, yielding 4 extra 90 degree turns. When you look at hydraulic flow charts, you'll see that is a disastrous reduction in cooling water flow. The result was charred FRP that wept then leaked in the salon. The three fixes were: 1. Vetus Wet Exhaust vanes 2. Upgrading to the Blue hi-temp pipe through the salon, and 3. Having NME rebuild the Wet Exhaust nozzles. Doing it again, I would re-work the Cummins heat exchanger to point the outlet directly up, if yours has the byzantine configuration. Photo attached. Paul: These are awesome boats. Not perfect, but really tough. I went through some steep short 5' chop that sent green water over the top. Wife would have divorced if she could have gotten off the boat J Hope these shots and comments are helpful. I spent about $550 on the NME rebuild at that time (about 2011). I'm guessing it would be $1k or more now. Our vessel was sold to a couple on Vancouver Island. They are now also retired. Best of luck to you. Cameron Sharpe CPP Board Certified in Security Management 7501 E. Thompson Peak Pkwy # 69 Scottsdale, AZ 85255 SharpeC@cox.net 480.540.3370