According to the latest information available, the Coldwater boat launch is a concrete ramp located in Coldwater, Michigan at the coordinates of 41.83382797 latitude and -84.98939514 longitude. The boat ramp is situated on the north side of the Sauk River, which is a tributary of the St. Joseph River.

The Coldwater boat launch is relatively wide and can accommodate multiple watercraft at the same time. It also has a decent slope that is suitable for launching boats and other watercraft. Additionally, the ramp has a parking area nearby that allows for easy access to the water for boaters.

As for the type of watercraft that are permitted on the water, the Sauk River is large enough to accommodate small to medium-sized boats, kayaks, canoes, and other similar watercraft. However, due to its size and depth, it may not be suitable for larger watercraft such as yachts or commercial boats. Therefore, it is important to check with the local authorities before bringing any watercraft to the Coldwater boat launch.

In summary, the Coldwater boat launch is a concrete ramp located in Coldwater, Michigan that services the Sauk River. It can accommodate multiple watercraft at the same time and has a parking area nearby for easy access. The Sauk River is suitable for small to medium-sized boats, kayaks, canoes, and other similar watercraft.