Onassis did not want planes where his ships were operating ...
OK, but (contrary to what that article says - "only a tiny proportion of which have airstrips") most of the Greek islands we have heard of do have airports, and are served by Olympic flights from Athens. So the ferries already have competition.
As I see it, the use of floatplanes would be for the smaller islands, or to get to private jetties, but again I can't see the competition angle there.
I also wonder how useful a Cessna-type floatplane is on the open sea. The Med is not a lake.
Less bumpy than the North Sea, though. Didn't Imperial Airways operate flying boats to Alexandria? From Greece, or Southern Italy?
Floatplanes were until recently blocked by an endless loop or requirements to operate, making it same like forbidden. The reasons are that the state could not handle efficiently who controls these flights-sailings ; CAA, Port Police or both. Then came in customs control issues as well as immigration.
Aegean sea is an eastern border of the EU. Even though you can use many ways to cross to the east, the floatplane was always considered as an easy way to smuggle things in and out of Greece with little room of control by authorities and hence the loop of requirements that were blocking them.
To be honest the idea of island hopping & south med. weather sounds inviting for floatplane flying but as some of you may know floatplanes rely on calm water. Greece has an excellent weather but when it comes to waves in the Aegean sea during summer winds (meltemi) the conditions are prohibitive with the exception of only some protected small bays which do not always coincide with ports/docks to disembark.
As mentioned also most of the islands have frequent connection by sea and air and the -not depending on wave conditions - competition was always there.
Recently things are improving in the sense that legislation is being introduced to make room for some form of floatplane activities without hassle.
Waterdromes and water ZZZZ landing strips will become more simple in being established by local municipalities or even locals. Some of the former already exist but not the later. Still there will be some control in the situation like involving authorities in flight prior notification or with waterlanding allowed only in above established sites but this is much better from before since these sites will be much easier in being established.
Some waterdromes were established few years ago by and for the use of a Greco-Canadian company, Air Sea Lines, struggling to establish a scheduled air service between few ports. The hurdles were so many that after a couple of years of operating scheduled flights they gave up since it was not profitable awaiting further developments.
Though I cannot comment on the regulatory factors, I can confirm that a sea is no place for a float plane. A Twin Otter has a hope in very good sea conditions, but it is exceptionally large for a float plane. More than one foot waves, or 18 inch swells are very challenging for safe operations, and no damage to the plane. And, salt water is terrible on planes. I've flown a few times in the ocean, but in very protected harbours and fjords. When the plane is put away after the flying, it must be removed from the water, and fresh water rinsed. This requires a lot of facility. Though amphibians can make this much easier, they typically have a lesser useful load and increased operating risk, which makes them un competitive for commercial operations, particularly compared to a landplane, when runways are available.
