Atomic 4 exhaust
You can''t use hose directly from the engine as the dry engine heat will melt it. You will notice that a hose injects water somewhere along the pipe you have described. From that point on to the outlet you can use hose.
You can get the adapter flange from a number of atomic 4 parts sources. Then go to the hardware store and reproduce the pipe by piecing together galvanized pipe fittings. Check it every 2-3 years in salt water for needing replacement.