On this page: http://www.freesurnamesearch.com/search/africa.html
you will find quite many helpful links, as:
Port Napoleon, Isle de France 1808 Census of Professionals (today Port Louis, Mauritius). Mauritius is an African island located in the Indian Ocean and an independent country (In French).
Emigration from Brittany and Normandy to Mauritius (In French)
Civilian Passengers from the Ports of France to Mauritius and Réunion 1717-1810 (In French)
Mauritius Genealogy Search at Geneanet
Mauritius 1776 Census. Mauritius, then Isle de France, is an African island located in the Indian Ocean and an independent country (In French).
Mauritius Notarial Act Index 1779-1809. Indexed by notary. For an overall surname index Click Here. Web sites in French.
Généalogie Mauricienne. Mauritius genealogy database. Over 50,000 individuals.
A link to genealogy newsgroups on yahoo of the region you will find on this page: http://gw1.geneanet.org/index.php3?b=hmaurel
Another hint, if your ancestors may have been slaves, is to search the Slave Registry of the British Dependencies,
that is made available online by http://search.ancestry.co.uk/search/db.aspx?dbid=1129
Only for registered users (free) and not available on other sites of ancestry.com (ex. ancestry.fr)
I also counld t find it in other genealogic databases, seems like they made a deal with the British Gouvernement for exclusive rights.
Another good idea may be to contact the Mormons in Utah (no joke), they are very interested in genealogy and at least the made microfilms of Reunion registers and church books in the beginning of the 70ies.
I'd wonder if they didn't do the same with mauritius registers.
They got quite many online sites, as: http://www.familysearch.org/
but at least the Reunion databases have never been made available online.
As far as I remember they reply to written requests, and also send copies of the microfilms on request.