I forgot to mention that we booked all of our cruises on the day that we departed on that particular day and we booked directly with Major Marine and Kenai Fjords in Seward. We were there the days before the 4th of July and I would assume that is peak season. None of the boats were full - most were at 75% or less.
I have never heard any narration except for English on any of the day cruises. A lot of the narration involves directing people to look where the animals are. Perhaps since I have been on so many of these day cruises, I just tune out everthing except when an animal is spotted.
The boats all have restrooms; on many of the boats you cannot flush anything that you personally have not consumed; you may flush small amounts of toilet paper - but only the paper provided.