Is it possible to do a day trip from Amsterdam to the Afsluitdijk "Enclosing Dike) without a car? If so, what is the best way: train, bus, organized tour, other? Thanks.

Yes you can. Take a train to Alkmaar and from there by bus. Bus goes to e.g. Zurich at the other side of the Afsluitdijk or continue to one of the nice towns likes Makkum, Bolsward or Leeuwarden.
Train to Alkmaar will take about 30 minutes, bus depending to which place about 1,30 hour.
The site is in dutch, but by putting in your starting and destiantionpoint it will give the schedules.
www.9292ov.nl

I took a day tour offered by the tourist office. It went to Friesland via a boat ride across the Ijselmeer to Makum where we had a walkabout and visit to a market then back on the bus to another smalltown and walkabout. The last stop was the dike and then it was back to Amsterdam. It was a full day, most informative and covering a lot of ground most efficiently.


The tourist office (near the Central Station) also runs several day tours which are equally well done.

irishface - thanks for the tip. Do you recall who ran that trip? Was it through the tourist office at Central Station?

Guy, it was run by the tourist office. The one by Central Station is where I booked it and where I went to board the bus and where the bus left us off at the end. (oops sorry for the run on sentence.)