Thanks so much for your local perspective. Especially the confirmation about the local reaction to missing tourists in Hawaii.
It's going to be very important to keep Sam in the media spotlight - both mainstream and social - until he is found. Some great ideas have already been mentioned and I've seen others mentioned on Facebook:
-Contact Senator Hirono for help and advice. (The family should do this.)
-Contact other local officials
-Keep sharing his story on social media - not just Facebook.
-Reach out to local and national news channels with the story
-Post comments on the Kauai Police Dept FB, Twitter, Instagram, etc. Show that a lot of people care about this young man.
Log into Facebook
-If a friends or family members can't get to Hawaii to help with search efforts, consider hiring someone to do this. SAR groups in Hawaii??
-What else?