Well that's a different way to earn a living going to at sea.
Just thought about those three thousand series engines and seem to remember long time back some firm brought out a non Cat turbo to exhaust joint kit which was actually designed to snort out exhaust gas upon start up and heat seal itself when it got hot.
Could'nt ever see the point of it and remember Cat sent out a circular condemning it outright on the obvious basis that no exhaust should ever at any time exhaust any fumes into the engine room.
ie, gas tight at all times
Remembering The Good Old days, when Chiefs stood watches and all Torque settings were F.T.