Not sure if this fits in here, but maybe it will help someone out: I just found out yesterday that my University does hydrostatic testing for free (along with VO2 max, caliper measurements, and all sorts of other tests). There's a large exercise science program and students have to do a number of these tests on "clients" to complete their various certifications. It is all done under the supervision of experienced instructors. Sounds a little like getting your hair styled at the local cosmetology school, but maybe a little less scary. It might be worth looking into for folks who can't afford these tests or people that live far away from the usual labs, etc.