The Sleattemer Mar (also known as the Slotermeer) is situated between the three towns of Sloten, Balk, and Woudsend.
Three navigable channels, marked with buoys, connect these towns with each other; outside of these channels, the Sleattemer Mar can sometimes be only 1.20 meters deep. During the Elfstedentocht, the route crosses this lake twice, once from IJlst to Sloten and once from Sloten towards Stavoren.
Within the Sleattemer Mar, there is a speed boating area; within the yellow buoys, you are allowed to boat at high speeds. Outside of these designated areas, you must adjust your speed to accommodate other water sports enthusiasts.
