The Panama Canal Authority has set temporary draft limits for large vessels because of water shortages for the locks caused by an unusual weather pattern. The restriction essentially will require vessels to lighten load at ports of origin so they ride higher and less water is required to raise them in the locks. El Niño, a climate phenomenon resulting in periodic warming of the tropical Pacific Ocean, has changed the rainfall pattern in Panama, triggering a drought in the canal watershed and causing water levels in Gatun and Alhajuela lakes to fall substantially below their average for this time of year. The Panama Canal Authority’s (ACP) shipping advisory sets the maximum draft at 39 feet in fresh water, effective April 18. Vessels loaded to drafts over 39 feet prior to or on March 21 will have their draft restriction waived for transit, subject to safety considerations. Vessels loaded after March 21 will not be allowed through the Canal if they draft below 39 feet. Further restrictions could follow, the ACP said.