I'll let others detail the benefits of USNSA and recognition of their certification as it relates to charter companies...but...I'll quickly take the opportunity to throw out an endorsement of the Pentagon Sailing Club. I'm a fairly new member and my impressions thus far...
- Experienced and knowledgeable club leadership
- Willingness to teach in a constructive manner - haven't seen an ego flare up yet
- "All are welcome" attitude / friendly atmosphere
- Highly-structured and documented learning program
The latter was what really made it a no brainer for me. The club appears to be completey focused on educating new and old sailors alike. I know this doesn't directly answer your question, and I'm not trying to make a commercial here...just my two cents. Good luck.