Complex sentence: The MS Nordkapp sister ship of the MS Nordnorge, built in 1997, tours Antarctica during the southern hemisphere summer.during the European summer it runs off the coast of Norway.
Split into simpler sentences: The MS Nordkapp is the sister ship of the MS Nordnorge, built in 1997. It tours Antarctica during the Southern Hemisphere summer, and during the European summer, it runs off the coast of Norway.