Ballast is a heavy material used for improving the stability of a ship by stowing it in the bilge. This song was a favorite of the fishermen and ballast workers of Terschelling and other Frisian Islands. At low tide, the men took baskets from the flats and hoisted it aboard by the ship's yardarm where other workers would stow it in the hold.
Surinam is Dutch Guiana, on the coast of South America. Along with Curacao and Aruba, it was an important port, particularly for hardwoods.