Find below latest update for LNG booking slots spaces:
December 10th to December 12th: NO SPACE AVAILABLE.
December 13th, 2017: 1 space available for LNG Northbound
From December 14th to December 31st: NO SPACE AVAILABLE.
NOTE: You can revert with LNG Vessel tentative ETA and arrival side (Atlantic or Pacific) in order to provide more accurate information
Regarding slot availables (if any), etc.
Alternatively to look/find booking slots available on daily basis, you can access below link (this web page is updated by Panama Canal Authorities every 30-60 minutes AGW):