Captain's family

My G. Grandfather, Johan Rostad was born in 1839 in Inderoen and was a Captain in the Merchant navy. I get confused with the Norwegian change of names but he was married, I think, to Oline Andreasdatter or Andersen, born in 1849 in Sparbo Pr. Johan Rostad's daughter, Abelone who was born in Stenkjaer in 1878 was married in England in 1911 The family is still recorded as resident in Norway in the 1900 census. But somewhere between the census in 1900 and the wedding in 1911, the family moved to England and Johan died. ( In Abelone's marriage certificate of 1911, Johan, her father, is listed as deceased) How do I discover:- 1. When they left Norway 2. Which ship Johan was Captain of 3. How and when he died. I have another problem. Oline's mother was Abelone Olsdatter born 1821 in Sparbo. In the 1865 census she appears with her mother, Abelone Andreasdatter but Abelone's husband, Ole Arntsen is not, I think, Oline's father. From my research, I have a feeling that her father may be Anders Hansen. Abelone and Ole subsequently had a son, Arnt Olesen born in 1857 in Sparbo. How and to whom does one apply for marriage certificates in Norway? I need to tie Oline to Anders Hansen. I would be grateful for some assistance in all this - these Norwegian surnames are doing my head in!!!! Susan.