Translation:The singing men were on a ship far out on the sea.
Both yes and no. According to Gyldendals dictionary the english word 'ocean' can also translate to 'hav', as in the danish translation for The Atlantic Ocean; "Atlanterhavet", The Pacific Ocean; "Stillehavet" and so on. So 'ocean' should be perfectly acceptable. (On a side note for those interested, the word 'sea' is also at rare times translates to 'sø', mostly in fixed expressions like 'søens folk'; sailors, or 'Østersøen'; the Baltic.)