5 /5 John Hsieh: An actual functional boat lock leading to the Black Rock Canal. A great sight to see while visiting Unity Island Park. The entrance of the lock is accessible by foot paths from the park. The lock itself is access controlled, but you can still see the occasional small boats pass by. Not sure if its a great spot for fishing with all the boats passing by, but there was somebody sitting at the end of the pier trying to catch something...