We are a group of 4 with back to back cruises out of Piraeus scheduled to depart Saturday, May 10 (2025). We are trying to determine our schedule to include 2 nights in Athens and 2 nights on the island of Hydra. My initial plan was to arrive in Athens early on Tuesday, spending Tuesday afternoon and Wednesday seeing the sights in Athens (we will also be in Athens another day between cruises. Then to get a little different feel of the country and relax prior to our port intensive cruise, taking a ferry to Hydra on Thursday morning spending 2 nights on the island. Finally, Saturday morning taking the ferry over to Piraeus to board our cruise around noon. This seemed to make the most sense as we would not be duplicating trips to Piraeus. We don't think we would enjoy Hydra as much after our cruise.
After reading other posts, I have verified that Orthodox Easter is in April and will not affect our ferry. I am concerned about the possibility of a strike impacting us. Is this a realistic concern? And if so, normally how far in advance could I reasonable expect to have to adjust my plans.