Flight or Ferry from Naples to Palermo?

How well do you sleep on a ferry boat? Depending on time of year, weather could be an issue.

If weather is not likely to be an issue and you can sleep on the boat, that sounds better than getting up at o'dark ugly to catch a 7AM flight

My purpose is trying to make my travel the most sights with
cost-effective, time efficiency, and safe.

In that case, take the ferry. It will save you the cost of one hotel night and travelling while sleeping is very time efficient.

I have no experience with that particular ferry, but I've taken two other European overnight ferries and found them very comfortable for sleeping. (I would definitely not say the same about night trains.) In your shoes I'd choose the ferry.

That 7 AM departure from Naples doesn't appear to be your only option. Am seeing several other direct flights later in the day for as little as 20 Euros. Even with the ala carte pricing for baggage that's still a pretty cost-effective way to go.
It really comes down to what's more important to you when you travel - your money or your time?
Flying over in the afternoon or evening would save you time that could be put to good use exploring either Naples or Palermo.

Flying over in the afternoon or evening would save you time that could
be put to good use exploring either Naples or Palermo.

Flying will not save time compared to taking the ferry.

We took the overnight ferry in the other direction, from Palermo to Naples, and it was wonderful. Scenic leaving Palermo just after sunset. Slept like a baby myself although others said there were some rough spots during the night. Woke up to Naples in the morning. If you're not a terribly light sleeper I would recommend the ferry crossing. The only caveat is that you have to purchase so far ahead that you won't know what the weather may be like and you have to take your chances. If you're thinking you might like the overnight ferry crossing then definitely do some research on the likely weather at the time of year you are contemplating. We did it in September and weather was very nice.

"Flying will not save time compared to taking the ferry."
I believe you'll find that it does ... 1 hour by air versus 11 by sea.

"Flying will not save time compared to taking the ferry." I believe
you'll find that it does ... 1 hour by air versus 11 by sea.

A one hour flight is not one hour travel time. You need to get to and from the airport, check in, go through security checks and so on. A one hour flight usually means at least 3 often 4 hours travel time.

The ferry on the other hand is overnight so most of the time will be spent sleeping, something you have to do anyway. So with 8 hours sleep and 30 min in the morning and 30 min in the evening getting ready, that 9 hours that you would otherwise have to spend in a hotel. So in reality, the ferry trip is only 2 hours of awake time. 2 hours that are a lot easier to use than the 3-4 hours of standing in line at airports and sitting in a cramped airline seat.

Comes down to personal preference I suppose. While there is indeed something to be said for the "port to port" convenience of the ferry, traveling by boat is just not our cup of tea. We've generally found that the overall scuzziness of the experience far outweighs any real or imagined cost savings, and the last time we were able to get 8 hours of sleep on any boat was during the Eisenhower administration.
In this particular case we would opt to fly - would much rather get there quickly and with a minumun of hassle, preferring to spend the evening strolling around Palermo rather than being confined to a ship ... but that's just us. The OP may well have different goals and priorities, and may prefer the boat ride if he/she believes that to be the best use of their limited vacation time.
To each their own.

"a minumun of hassle"

When was the last time you flew???

The last time I can remember "a minimum of hassle" on an airplane flight was sometime in the 1970's.

And when was the last time you took a ferry from the port of Naples? I can assure you that it isn't a pleasant or hassle free experience.
Personally, I'd prefer the short flight versus being stuck aboard ship for 12 hours - hence the suggestion to the OP to consider all options before committing.

Since I spent a few years in the Navy, I do not consider spending 12 hours on a ship as being "stuck". It is rather enjoyable compared to being "stuck" inside a tube.

Am reminded of Samuel Johnson’s famous quote after spending time with the Royal Navy: “being on a ship is like being in jail ... with the added danger of drowning”.
Thanks for your service Bob - 30 years for me.

Another Robert chiming in. I don't ever recall anyone posting positive comments about the ferry between Naples and Palermo. In fact, when I looked into doing that 2 years ago, there were plenty of discouraging comments. Just saying. That said, what would be wrong with some extra time in Palermo? And, keep searching airfares. Lower is possible - I just got my $16 refund from Alitalia for my Rome-Catania flight from last month. Yes, that included luggage.

I would take the ferry just for the novel experience!
You can fly any old where, but you can't always take a boat.

My travelling - Southern Italy and Sicily has set in late September 2021 to October 18, 2021
I'm planning to leave Naples on Wednesday, 6 October 2021 to go to Palermo. EasyJet has not published a new schedule for October 2021 yet. I have checked EasyJet Wednesday schedule in September 2021 and found it has only flight that operates from 7:10 AM to 8:10 AM. I will wait and see EasyJet published schedule for October 2021.
The flight will be quicker. However, I have to get up too early to catch a 7:10 AM flight. Being stuck aboard ship for 11 hours sounds too long. But, it will be my sleeping time. My concern is safe or not for a woman 65 year-old, solo traveler like myself for overnight ferry crossing?
I think likely, I will vote the overnight ferry crossing for the novel experience. I definitely do some research on the likely weather September and October of previous year and hoping in October 2021 the weather will be nice.
Thank you. Much appreciated your input!

My concern is safe or not for a woman 65 year-old, solo traveler like myself for overnight ferry crossing?

The boat has no idea how old you are, so its likelihood of sinking is not influenced by the age of the passengers.