[1] He was a new name in Norwegian and international kayaking after 1945, as most of the pre-war organized sporting activity had been put on ice during World War II.

[2] Already in 1948, before the Summer Olympics that year, Østby and his teammate Ivar Mathisen were considered as having the highest medal hopes in the Norwegian canoeing squad.

He was considered as being without any sporting hopes for the competition, having no prior experience with whitewater kayaking—the newspaper Verdens Gang quoted him as saying "I don't even know what kind of boat to use".

[5] The participation was essentially regarded as a test to see whether slalom kayaking should be taken up in Norway—where it was largely unknown, despite the country's abundance of whitewater locations.

Østby was the only competitor from Norway, but the vice chairman of the Norwegian Canoe Association traveled with him to help evaluate the championship.