There are some bilateral agreements but most seem to apply to Aussie and NZ citizens.
Once you move outside the Schengen tourist visa ( wavier scheme) you are largely in the land of residence visas of one form or another. I’m familiar with
Greece which has such a process .
France has two long( er) stay visas the second one is essentially a residence visa.
All require significant paperwork and many must be applied from within the country. ( for example Greece requires a police visit and finger printing ) most have various stipulations to to
health insurance and source of funds etc.
Do not under any circumstances actively overstay and never seek the “ mercy of the
customs dudes “ who have nothing to do with it anyway.
The reality is to extend your time in the Schengen area requires you to acquire one or more extended national visas
Note also that having an extended visa for one country does not extend the Schengen time in another
So in practice you have three options
(A) after using up your 90 days , spend enough time in a non Schengen country to recover some Schengen days to complete your Schengen country visits. This could mean upto 90 days out of Schengen . Note this is just the crew. The
boat can remain for 18 months. However if your using the boat to live on , that would suggest
Gibraltar ,
Morocco ,Albania ,
Croatia or Montenegro could be used to “ hide out “ (
Croatia is joining Schengen ) the U.K. and
Ireland are too far away from G-I-F to be useful.
(B) leave the boat and fly home for 3 months to return for another 3 months
(C) decide on a Schengen country to stay in to recover Schengen days and apply for a long stay visa. Contact the relevant embassies in advance to establish what long stay visa program suits your needs. Do this way before the needed dates as some are cumbersome processes and take time. Some require you to complete the process in the country.
Personally at the moment I wouldn’t feel comfortable long staying in any North African country
So the obvious one would be to plan on France and eastern
Italy /
Corsica , Sardinia and
Sicily in the first 90 days , make a run to Croatia and then
work westwards back through the
Adriatic Ionian , Crete, Balearics etc, presuming you intend to cross from the
Canaries , you’ll need to aim to be there by October
The
canaries is also in Schengen and also represents an issue of time allowance
Even two periods of 90 days is way to short to explore G-I-F. My last sojourn in the southern
Ionian took 2 months and I covered 200 miles in that time !!! ( I’m EU so no time limit. ) I like to often spend 4-6 days in a port or anchorage
Id would personally recommend you fly home to avoid peak Med tourists months and try to
cruise in the spring early summer , early and late autumn. Peak summer is crowded , expensive and hot.
To really cover the ground you mention especially if you would like to cover the Greek and Turkish Aegean islands as well as the
Adriatic countries will take 2 years or more.( I ten years exploring France Italy and Greece !!!, having recently moved from France to Greece )
Unfortunately for non EU citizens the Schengen Agreement that facilitates free movement within the agreement countries is quite time limited as it was simply intended to mirror the visa waiver scheme adopted by the US.
There is no “ practical way “ to extend that Schengen visa waiver , there are “ hardship “ extensions but these are not easy to get and very specific. ( and typically get you about two weeks )