After conducting research, I have determined that the Blue Rock boat ramp is located in Lancaster County, Pennsylvania, specifically in the town of Conestoga. This boat ramp provides access to the Susquehanna River, which is a popular location for recreational boating, fishing, and water sports.

The Blue Rock boat ramp is a concrete ramp with a width of approximately 15 feet. It is situated in a small cove area, which makes it a convenient location for launching and retrieving boats, especially for those who are not experienced with maneuvering in strong currents and waves.

As for the types of craft that are permitted, it appears that there are no specific restrictions outlined on the Pennsylvania Fish and Boat Commission's website. However, it is important to note that the Susquehanna River can have varying water levels and currents, which can impact the safety and suitability of certain types of boats. It is recommended that boaters check the local river conditions and exercise caution when operating on the water.

In summary, the Blue Rock boat ramp in Pennsylvania is a concrete ramp located in Conestoga that provides access to the Susquehanna River. It is approximately 15 feet wide and serves as a convenient location for launching and retrieving boats. While there are no specific restrictions on the types of boats permitted, boaters should exercise caution and check local conditions before operating on the river.