We choose the 10 o'clock cruise and were happy we had done so. There was fewer people, everybody went for the top floor and we had the bottom floor almost to our own, shade garanteed. The sights are wonderful and the commentaries very useful. The boat may not be the nicest you have ever seen but it is comfortable and well kept. We bought our tickets online, through a group sale, ahead of time and enjoyed a nice rebate.
A worthwile experience to discover beautiful Naples, from the water.