Might he be interested in club sports? They are in between the intensity of varsity and the (usual) casualness of IM and recreational sports, and typically you travel and represent your school against other schools, which is fun. They typically have open tryouts, and while prior experience is often helpful, you don’t necessarily need it if you are a decent athlete and willing to learn. There are also sometimes no-cut teams.
Like many LACs, Mac has a pretty good range of different club sports:
I note that is the highest level at Mac of those men’s sports for Ultimate, Skiing, Water Polo, Volleyball, Rugby, and Ice Hockey (I might have missed something).
IM is also a thing at Mac as well:
It is a somewhat overlapping but overall different mix of sports. Generally you are looking at shorter seasons, much less practice, and of course no travel.