Extracurricular Clubs

In poring over the USNA website, there's a huge number of extracurriculars that my DS can be involved in (seriously...a ton!). His big sister loves her involvement with Cru and Navigators at her university. Does anyone know how active Cru and Navigators are at the Academy?

Thanks so much in advance for any replies. Also, if this isn't the right forum, just point me in the right direction