The bird was sighted by ferry passengers travelling from Hull in England 16 kilometres off Zeebrugge. Naturalists say that if the Belgian Rare Birds Committee accept this sighting it will be a first for Belgium.
It's believed the same bird has also be seen off the coast of Britain.
The brow albatross has a wingspan of 2.5 metres and weighs some 4.6 kilos. It can live to the age of 70. The species got its name thanks to a fine black stripe above its eye. Sub Antarctic islands in the South Atlantic form its usual breeding grounds.