Durban South Africa

My information is that my great great grandfather Ole Olsen (oh this should be fun) born in March 1835 Stavanger married Bertha marie born in November 1836 in Stavanger. both died in Durban, South Africa 27/10/1909 and 02/09/1906 respectively. there were 6 children, some or most ofwhom were born in Norway, some came to south Africa, and others stayed behind. There is a legend that one of the children was born on the ship on the way to South Africa. Children were 1 Martha Raswith(Rostring) stayed in Norway 2 Olaf Berthinius(My great grandfather) brought his parents, brothers and sisters to SA Born 1868 Stavanger, appears to have died on the same day as his father 27.10.1909?? 3. Ingwall (brother) 4. Gudmand (brother) 5. Ingeborg Christina (Grung) 6. Anna Olaf Berthinius Olsen married Agnes katrina magdalena on 02.04.1902 at Isinganbusi Church Kranskop Natal I would like to find out more details about where this family orignated from and when they came to South Africa. There are a lot of Norwegian descendants in South Africa. From what I understand there was a large 'fishing" community along the south coast of natal. anyone have any further info. Would be really interested and grateful Thank you Carla (what else!!)