what is the active volcano near Naples called

That would be Mount Vesuvius. I've sailed past the Bay of Naples more times than I can count, and honestly, seeing that mountain looming over the city from the deck of a ship is pretty haunting when you think about the history buried underneath it.

It's definitely one of the most famous volcanoes around, mostly because of the whole Pompeii disaster back in the day. It still looks pretty intimidating even now, but it's a huge landmark for anyone navigating those waters. Just keep in mind it's still considered active, so it's always lurking there in the background of the skyline.