We traveled from Amsterdam to Basil with a tour group, and were not given an opportunity to specifically book our cabin. We booked a Category 4 room. We were given room #234, next to the engine room. The noise was deafening and the vibration was huge. The ship traveled upstream and was at full throttle some nights. Even when it was traveling at normal speed throughout the night, there was a great deal of noise and vibration making it nearly impossible to sleep. Items literally vibrated off the counters. At times, we felt that we were vibrating off the bed! We could not hear any of the captains announcements, and that was when the boat was at a slower speed. One day, our room was filled with the odor of fuel oil, which remained in the room for several hours. The ship was fully booked, with no available cabins for us to move to. Of great concern to us, was the fact that the crew (captain, hotel manager, housekeeper and bartender) were all aware that this room was a "problem". We were told that they usually "have to move people from this room" on every cruise. The rest of the ship was beautiful. The food was wonderful. The staff were great and the itinerary was fantastic. Unfortunately, we missed 3 breakfasts, 2 lunches and excursions due to falling asleep after the ship docked. We also went through our days often feeling ill and sleep deprived. Room #234 should not be assigned during trips upstream and particularly not in the price category and without letting guests know about the noise. This should have been the "trip of a lifetime" and we are very disappointed that we were unable to fully enjoy it.