dddc

Ferries can be taken for longer routes and I have acquaintances that frequently come off flights from Australia (20hrs or more), hop on a 3 hour bus from Athens to Patras and then a 5 hour ferry to Kefalonia and Ithaca. Waiting for a flight would mean an overnight stay as you'd miss the ferry connection on Kefalonia (no airport on Ithaca).

April will have a couple of days of unsettled weather normally - but with the changes due to global warming, who knows what the weather will be like.

The greatest challenge will be trying to find schedules. Using this site https://www.ferries.gr/greek-islands-ferry/ you'll see future dates won't be available for some routes. I've been doing Kefalonia - Ithaca almost yearly for the past several years and the service has been pared back, ramped up, cut down continuously. You don't know for sure until the timetable gets released in the few weeks before sometimes!

nk15

This is my favorite 6 Beaufort ferry trip review in the Aegean sea, typical on Tripadvisor, translated...

το χειρότερο πλοίο - Review of SeaJets, Santorini, Greece - Tripadvisor

KLouis

Just adding one of many stormy, rough sea experiences of my life using ferries (about 25 years ago). Patras to Venice, in order to spend a few days around the end of the year with my sis who would join us there, coming from Germany. We left around 6 pm on December 29, and the boat started rocking immediately after exiting the port. A couple of hours later my wife and oldest son (both prone to sea sickness) stayed in the cabin in spite of taking antihistaminic pills, while my youngest son and I made our way to the empty dining room. After enjoying our dinner we made it back to the cabin trying not to fall, founf the two remaining members of the family sleeping (side-effect of the antihistamins) and stayed awake for quite some time due to the stereophonic moises of puking coming from both cabins next to hours. Early on in the morning we went to the deck to enjoy the views of Corfu, and then to the dining room for breakfast. This was, again, almost completely empty, and I was asking myself how much money the shipping company would be making on this trip. The Adriatic was really calm, the anemic sun was out there and we enjoyed the trip. Around noon, we made out way to the dining room and were shocked! I had never, ever seen such a crowd-packed place on a boat, not even when travelling in mid-August. We realized that the empty dining room earlier on was due to the fact that these hundreds of passengers were either all sleeping after swallowing their anti-sea sickness pills, or they had spent hours throwing up in their cabins finally falling asleep whan the storm passed. The return trip a few days later was... normal! By the way, we also had the chance to see a snow-covered Venice: AMAZING!

nk15

My new resolution for island travel in the Aegean, for any ferry trips over 2 hours, in August, is the following:

If it has an airport, take a plane. If it doesn't have an airport, take a plane to the nearby island airport (if there is one), and then a ferry (if there is a connection).

I had to change ferry tickets to planes this August, due to weather, so never again. We were lucky there were last minute 5k A3 awards and it worked out great with the plane and ferry schedules.

HogwartsExpress

Schlepping around to get to and from Corfu seems to me like an awful waste of time, but I’ve never particularly seen the appeal of the place or the Ionian more generally. Flying to Rhodes in the first place makes sense - and maybe to Heraklion from Rhodes - but otherwise I really don’t know why you’re flying at all.

WandertheWorld

We went to three Greek islands last year, two Ionian (Corfu and Cephalonia) and one in the Cyclades (Folegandros). Quite frankly Corfu was underwhelming except for Corfu town which , because of the Venetian inspired architecture, was very enjoyable. Otherwise we found it to be too over developed, jam packed with tourists even during mid September. On the other hand Cephalonia was beautiful and much, much less developed. Stunning sandy beaches and the town of Fiscardo was charming even if a tad too touristy for our tastes. Folegandros turned out to be Santorini without the crowds. No caldera but stunning dramatic steep cliffs perched high above the Aegean.

As to transport, we found that the Ionians were not well connected by ferry. There was no direct way to get from Corfu to Cephalonia which meant any sea based journey took many hours. Instead we flew, going first to Corfu (which has direct service from some European hubs) then took Aegean for the rest of the inter island transport. It worked out very well. Planes were newish and on time. Transfer in Athens was easy, even with connections times of only an hour. Luggage followed with no drama. The only unpleasant journey was from Santorini (Folegandros has no airport) to Folegandros. There is a scheduled public ferry but the service is limited and did not align well to plane schedules . So, we took a private boat. And, that trip was terrifying. It appeared to be average weather days on the Aegean both ways with the typical fall winds but nothing particularly bad. For 1.5 hours we literally bounced our way to/from Folegandros. I was thrown from my seat several times. I don’t swim and my spouse grew very concerned about the sea conditions and my safety despite the captain saying they were typical for early fall. I am prone to seasickness but frankly was too scared to even notice. I kissed dry land when we arrived.

KLouis

I certainly understand how badly you must have felt; one of my sons often gets seasick while I've never ever had the "pleasure". On the other hand, the captain has by law (of nature) no authority over the wind, while "common" law regulates when they're allowed to sail. I also think that a very small minority suffers from a pre-suicidal syndrome. Actually, the next time take a seasickness pill before sailing and everything will be fine. By the way, most of the Cyclades offer a great vacation and some of them (no names for obvious reasons) are still in the... '60s as far as tourist numbers are concerned; Ios, Mykonos and Santorini are clearly not among them. Finally, I also share your opinion on Crfou and Cephalonia (I looove that one!).

Boraxo

Ditto. We are planning to visit this summer and will stay on Santorini, Mykonos and Paros. We will take ferries between the islands but plan to fly to/from Athens.

This matches my experience as well. It's been decades since I took the ferry from Athens to the Cyclades but my recollection is that schedules are never exact and the boat rides are looong. And I get queasy on our 30 minute local commuter ferries that cross the SF bay.

I loved Corfu but maybe it's different when you're in your 20s and can scooter around the island. Speaking of which, I still have a small scar on my leg from crashing the scooter, thankfully no worse as I don't believe they rented helmets at that time.