When does the duty to exercise extraordinary diligence commence and cease with respect to transport of passengers?

The duty of the common carrier commence from the moment the person who purchases the ticket from the carrier presents himself at the proper place and in a proper manner to be transported. The relation of carrier and passenger continues until the passenger has been landed at the port of destination and has left the vessel owner's dock or premises. Once created, the relationship will not ordinarily terminate until the passenger has, after reaching his destination, safely alighted from the carrier's conveyance or had a reasonable opportunity to leave the carrier's premises. (Aboitiz Shipping Corp. v. CA, G.R. No. 84458, Nov. 6, 1989)