The Voorsters lock is located in the Zwolse Vaart, near Marknesse, and was completed in 1941, The lock has a height difference of 7 metres. The lock complex consists of a lock, a pumping station (Smeenge pumping station) and a movable bridge. Through the lock, boats can exit the Northeast Polder, onto the Zwarte Meer, or enter the Northeast Polder, onto the Zwolse Vaart.