The large will be closed to boat traffic from Nov. 5, 2013 until Nov.
20, 2013 so that the lock can be inspected and maintenance performed as
necessary. The small lock is still operating for smaller vessels. Even
though you won't be able to watch the large vessels locking through, It
is still worth a trip to see and appreciate the enormity of this site.
The large lock almost emptied.
Here is a link to a previous post describing the process and with pictures taken during the closing