Based on the latest information available, the Amsterdam Dunes Preservation Area boat ramp is located in Sheboygan County, Wisconsin (latitude: 43.55755615, longitude: -87.79199982). It is a public boat ramp that services Lake Michigan, which is a large freshwater lake located in the eastern part of the United States.

The boat ramp at Amsterdam Dunes Preservation Area is reported to be 20 feet wide, which should provide enough space for most boats and watercraft to launch and retrieve. However, it is always recommended to exercise caution and follow standard boating safety procedures while using the ramp.

As for what kind of craft are permitted on the water, it can vary depending on the specific regulations and rules in place at the time. However, typically, Lake Michigan allows for a wide range of recreational watercraft, from small fishing boats and kayaks to larger motorized vessels like speedboats and yachts.

Overall, the Amsterdam Dunes Preservation Area boat ramp provides a convenient and accessible entry point for boaters looking to explore the beautiful waters of Lake Michigan. As with any outdoor activity, it is important to check for any updates or changes to rules and regulations before heading out on the water.