If my father's unlabeled and un-indexed slides are in chronological order, which I believe they are, then he visited Gloucester, Massachusetts in the summer of 1954, shortly after graduating from prep school at The Loomis School in Windsor, CT.
I had no idea where these photos were taken until I used a Google image search to help me identify this statue.
My search revealed that this is "Man at the Wheel", also known as The Gloucester Fisherman, in Gloucester, MA. Once I had a location I looked for Catholic churches in Gloucester, MA
to see if I could identify these photos of an alter and a church.
The church is Our Lady of Good Voyage, originally built in the 1890s (and rebuilt after a 1914 fire) to serve the Portuguese population in Gloucester, which was then the largest Portuguese population on the East Coast. When I first scanned these images the flags made me think of a regatta, but a second look told me it was probably some sort of religious festival. Well, now that I had a location, it was easy to find and answer. Dad's photos are most likely from the Blessing of the Fleet, an annual event in Gloucester and, at the time, a very big event.
You can see even more photos on the Good Morning Gloucester blog. There is a six part series of photos from 1948 that starts here and if you're really interested you can do a search for "Blessing of the Fleet" on the blog for even more photos.
Dad's photos sure are giving me the travel bug!