From the US Army Corps of Engineers website, some information on the lock closures in October and November.
"The Hiram M. Chittenden Locks in Ballard will close to much or all marine traffic at various times Oct. 31, Nov. 1 and Nov. 5-20.
Vessel operators should pay close attention to times, vessel-size restrictions and impacts caused by railroad bridge maintenance.
On Oct. 31 and Nov. 1, U.S. Navy divers are scheduled to prepare the Adult Salmon Exclusion Structure for normal winter operations. Both locks are scheduled to be closed on Oct. 31 a maximum of four hours from 8 a.m. to noon. The large lock only is scheduled to be closed from approximately 8 a.m. to noon Nov. 1.
The large lock at the Hiram M. Chittenden Locks in Ballard is scheduled to close to all marine traffic from 9 a.m., Nov. 5, to 5 p.m., Nov. 20, for annual maintenance. The small lock will still be available for vessels less than 115 feet in length and 26 feet in width throughout the large lock maintenance period. Please note, however, that in conjunction with the Lock closure, BNSF Railway will make structural upgrades to the Ballard railroad bridge which crosses Lake Washington Ship Canal west of the Locks. High mast vessels able to use the small lock will not be able to pass the bridge during the four BNSF Railway closures from 9 a.m. to midnight, Nov. 5, 7, 12 and 14."
Corps of Engineers main page
Army Corps info