Athens to Blue Star ferry time allowance

Gail -- when you say "Athens" do u mean Plaka area? Monastiraki? It would help to name location... What I can tell you is that the best/fastest public transit is the "Green Line" to Piraeus. Here's a good map (scroll down):
https://www.athenstransport.com/wp-content/uploads/2011/06/Diktyo_Astikon_Sygkinonion_Athinon_en.png

WHERE to BOARD - If you are near MONASTIRAKI Station board Green Line going straight to Piraeus. Blue Star is just across seafront street from Terminus. If you enter Metro at SYNTAGMA Square, u must take BLue Line to Monastiraki & change. If your hotel is South of Acropolis, you'd get the RED line at ACROPOLIS Station, then change to the Green Line at OMONIA. NOTE - as a first-timer, I was reluctant to do line-changes on my own ... so I just rolled my bag a few blocks to get on at Monastiraki.

TIMING - Metro service starts 5:30 AM. Monastiraki-Piraeus = 30-35 minutes. Add 10=15 minutes to deboard, exit Terminus & across the street (there's a crossover bridge. Get your BS tix @ kiosk office on the pier; add 15 minutes if there's a line. So IMHO, you'd want to catch that Green line by 6:15, to feel safe. Boarding begins 15 minutes before departure, and the first people who reach the upper decks get the prime outside-deck seating (if u booked "reserved economy" that entitles you to a reserved indoor seat but u will want to sit outside part of the time, and that's first-come-firstserved).

If there is not a strike, and there are 2 or more of you (again, more data = better advice) you might consider a taxi; at 6:15 or so, less traffic, so no more than €22 from central athens. The outfit called "Welcome Pickups" has a good rep for reserving.

PRECAUTION - Let me say first that Greece is one of the safest countries in Europe, much lower rate of petty crime than other popular tourist destinations (Italy, Paris, London). On the islands virtually no problems with theft (except college kids in hostels stealing from each other!). And in Athens the main thing to be alert about -- pickpocketing -- is 95% confined to the Metro lines to/from airport and to/from Piraeus. There's apparently a "ring" of fast-fingered folk (in past roundups, mostly illegal Albanians) who target naive tourists carrying cash, phones, credit cards & passports carelessly in pockets, backpacks or shoulder purses. If you exercise ordinary prudence, you'll have no problem (I've taken both Metros at least 30 times in my various trips with no incidents at all - because I'm a former New Yorker and seasoned subway commuter). Here's the drill:

• Stow passport, cards, major cash, phone, in safe device UNDER clothes (men use money-belts; I hate bulk around waist, instead use a "neck pouch" that hangs inside shirt. I ONLY use this going via ferry or metro between destinations). Do NOT access this in public, to get something; it reveals location of your stash.
• Put what you'll need for trip -- ferry ticket, money for Metro or taxi, snacks -- in a change purse, in a pocket INSIDE your daybag (which I hope has a ziptop & you can wear it crosswise in front, with a hand on the closure).
• IF traveling with a male companion (you do not say), please persuade him to use a Moneybelt or else hand over all his valuables to put in your neck-pouch), and not to put anything in his pants pockets. His minor trip-cash should be in zipped top pocket preferably. Backpacks should be worn in front for duration of Metro ride.
• On metro, get seats if possible; otherwise, stand away from doors. A thief technique is to cause distraction jostling or bumping so avoid crowded spots in the car. Don't daydream or browse phone. All that being said, you probably will have no incident & not witness one. A prudent person is a happy person.

Dear Janet,

Thanks very, very much for your extensive information! My female companion and I are staying in the Plaka. Both of us have money belts. (I have traveled alone in Europe and Turkey several times). Forewarned is forearmed. I'be been following the strikes and think we'll be ok to sail Saturday. Thanks, again.