these little engines - called "mules" are what move the big ships through the canal...

as you can probably tell this was taken at night....we entered the Gatun locks well after dark...our advisor said that in over 10 years of piloting he'd never entered the locks that late...evidently there were no advisors available for the next day so the ACP told him to do whatever he had to do to get us through! it was beautiful and sort of eerie to be by ourselves in the locks at night. pretty neat actually....