Maritieme Afvalstoffen Inzamelijk Nederland, MAIN in short, is specialised with the collection of ship waste products from inland shipping, the fishing industry, and the shipping and offshore industry throughout the Netherlands. The company has a modern fleet of ”environmental boats”, tank wagons and trucks. Various Dutch sea ports have permanent collection points, such as in Den Helder, Den Oever, Harlingen, Stavoren, Amsterdam and Delfzijl. In Den Helder, on the Nieuwe Werk quay, MAIN has a harbour collection installation (HOI). The environmental boat MAIN II is stationed here.