As per the Boatigo Terms of Service, a Captain is only required to wait until the listed trip commencement time or the commencement time that was agreed upon using Boatigo's inbuilt messaging system.  After this time, if the Crew has not arrived, the trip may commence and no refund will be given.

It is highly advised, for the sake of community spirit, that Captain does attempt to message Crew (using Boatigo's inbuilt messaging) prior to departing without them.

You can view Boatigo's Terms of Service.