Based on the latest information available, the Greenbush boat ramp in Maine is a concrete boat ramp with a gravel parking area. It is approximately 20 feet wide and can accommodate small to medium-sized boats. The ramp provides access to the Penobscot River, which is a popular destination for fishing and boating in the area. The river is suitable for a variety of watercraft, including powerboats, canoes, kayaks, and other small boats. However, it is worth noting that certain areas of the river may have specific regulations or restrictions on watercraft use, so it is important to check with local authorities before launching any vessel. Overall, the Greenbush boat ramp is a convenient and accessible location for boaters and anglers looking to explore the Penobscot River.