All the SAR job over Western Africa (ocean + desert) is done by a lone Breguet Atlantique of the French Navy, positioned at Dakar - and it has been like that since 1960, year of independance. Crew and aircraft are rotated from France....Dozens of successful rescue operations performed since, like the South African Shackleton which crashed in Mauritania years ago.
So everybody flying or sailing there should thank the French taxpayers first (because ALL the local governments there simply don't care about what's happening out at sea)
Now maybe this aircraft at that particular moment was busy somewhere else (Mali ?) or they did try a little bit, or they were not informed in due time.....
You want some change there ? Your money is welcome !