To trace your Foo( Fu) ancestry in Hainan, the best bet is to Log into the website of http://www.fooclan.org.sg/ and look for "Contacts" you will find the mail box address, attention to Ms Gina Lee/Liaison Officer of FCA or call her at S'pore time between 1pm-7pm, Saturday and S'pore Public Holiday is her off day.
Theywill assist you on the tracing. You may see a lots of Chinese characters over other items which you will find unfamiliar in the web, they are taking steps to translate it into English. CH Foo
To see the history of Foo. click on to : http://www.fooclan.org.sg/?page_id=91 and look for the English version.