I am an USA Citizen aboard a USA flagged boat
currently in Preveza Greece
. I bought my boat
in Malta and sailed here via Sicily
in 2019. Yes you can sail from Turkey to Malta without stopping in Greece
. South of the Peloponnese and a bit of a long trip but doable. Grand Harbour Marina is wonderful and Malta is a jewel in the Med.
I believe that you can stop in a Greek port but you must quarantine for 2 weeks on board. I think that if you arrive without approval of the port police then its like a 5K euro fine for the boat captain
and 300 for each person.
A Dane friend and 2 crew recently delivered a new Cat from La Rochelle to Fethiye in a straight shot. I would not be excited about doing it alone.