My daughter participated in the half-day version of this swim camp at St Albans last summer:
https://summer.stalbansschool.org/sports/swimming
I don't recall the name of her instructor, but she was a professional swim team coach and her expectations for stroke mechanics are higher than what I've found to be typical of Red Cross-trained youth swim instructors, especially the college-aged ones who tend to staff recreational summer camps. My seven-year-old daughter did not love the high standards--she mostly wanted to play with her friends in the water--but as a former youth swim instructor myself, I was very pleased.
I will say that the St. Albans camps seem to be run more like extended-day sports clinics than, say, the more recreational Beauvoir and Headfirst camps at the same location. They are great for kids who really want to focus on a sport, but maybe less so for a kid who wants a side order of sports with the usual camp fare like singing, arts and crafts, etc.