The attachment looks OK; use of the words "indemnity," "indemnify," or "hold harmless," not so much.
I'm not a lawyer, but US Sailing has a bunch, which is why there is a prescription (RRS 82) stating that those terms (and intent) should not be used.
Waivers are OK, and this should be a very helpful link for you:
http://raceadmin.ussailing.org/Page1165.aspxMike
