Just back from our forth cruise on this lovely ship. Lots of soot and smuts on upper decks.
The crew clean hand rails, and mop decks on a continuous basis, and provide towels to use on the chairs. Without towels you would have damage to your clothes. I now have several shirts with black spots.
On one formal night we questioned the captain about this , and were told it is a problem for all cruise ships!!! , and not a problem with the fuel.
On our previous trips we did not notice this problem. The ship arrived in Dover and a very large crane was being assembled, and a very large new metal assembly on the dock side. Work had been going on in the funnel during the cruise, perhaps preparing for a major modification.
Why don't Saga admit they have a problem, and inform passengers accordingly.
Apart from the smuts the cruise was everything we wanted.
Hope Sage sort this out before our next cruise in the Autumn.