Babaomby is effectivelly nearby ( some hours of local boat ) Antsiranana (called also DiegoSuarez in french name). This place is GREAT from May to November, so in July it is a kite paradize only.
In July, you can also go in the south of Madagascar, nearby Tolianaro ( called also Tulear in frech name), there you ave plenty and hundred of kilometers of spot, wild and 100% nature. There is a guy organizing kitesurf, surf, windsurf adventure from his catamaran. You don't need to pay hotel or wathever, everything included with a gooddeal if you compare with a hotel, transportation to the spot, and also you will not kite alone.
His website: http://www.mada-surfaventure.com
It is french but just send him an email, it willbe easier for you.
Have a good trip, you will never forget. Maybe you will stay there forever