Wandelaar was a Wielingen-class frigate of the Belgian Navy. She was launched on 21 June 1977 at the Boelwerf in Temse. It was later commissioned on 3 October 1978. Wandelaar was the third ship in the Wielingen class. She had the pennant number F912.She was sold to the Bulgarian Navy in 2004. Wandelaar was refurbished and commissioned as Drazki ( Daring)and with the pennant number 41.Later in 2008 two other sister ships Wielingen together with Westdiep were sold to Bulgaria. Given a list of categories: company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work, what category does the paragraph belong to?
A:
Mean Of Transportation