Well, this is not great news for global commerce:

The number of vessels waiting to cross the Panama Canal has reached 154, and slots for carriers to book passage are being reduced in an effort to manage congestion caused by ongoing drought conditions that have roiled the major shipping gateway since the spring. The current wait time to cross the canal is now around 21 days.

Note that in favorable conditions, wait times can be hugely lower — just a matter of a few days. But now we're looking at three weeks.

(Anything that slows down shipping vastly impacts what's available on store shelves and how much you pay for it.)

The pileup has come after the Panama Canal Authority imposed water conservation measures amid the local drought. Most of the water in the series of locks that makes up the canal comes from the freshwater Gatun Lake, which sits at a higher elevation than the ocean.

A ship's passage can push out up to 50 million gallons of water from a lock.

Part of those rules dictate that ships must be 40% lighter before passing through the canal, requiring some ships to offload some of their wares before making the trip.

"This is going to get worse before it gets better," one captain told media.

Not good.

Here, meanwhile, is a great video showing how this amazing canal works: