Phil, Probably one of the finest freshwater dive spots in Africa and definitely on Lake Malawi is to be found off of Kande Island. The PADI dive school "Aquanuts" offers inexpensive, personalized courses and the owner, Phil Parker has over twenty years diving experience in Africa, both Scuba and Free-Diving. The school is based in Kande Beach Campsite, which is well worth visting anyway. For futher info, contact Phil Parker PObox 22 Kande, Nkhata Bay District,Malawi C.Afica. Keep in mind the post is very slow. Directions to the campsite are available in any good, up to date guidebook.