Cancelation of the Port of Mazathlan, Mexico

Carnival has the right to drop and change ports when ever the need
arises. They will not put the crew, the passengers or the ship in
danger. You booking the shore excursion through a private vendor is
your responsibility not Carnivals. When ever you book a private
excursion you are then taking full responsibility for any losses. Had
you booked with Carnival you would be getting a refund or Onboard
Credit. Since you chose to book privately, Carnival owes you nothing.
Did you perhaps take trip insurance? If not then you are pretty out
of luck. Reading your Contract of Carriage would pretty much answer
any questions you have about port changes and any other issue.

Copied and pasted from Carnival.com legal notices section. You will
find this in your cruise documents as well.


ITINERARY CHANGE PRIOR TO DEPARTURE:
If Carnival has adequate notice prior to sailing that a vessel will
deviate from the published itinerary it will promptly – upon making
the itinerary change -- notify guests of the change through their
travel agents or directly, in the case of a direct guest booking.
If the itinerary change is for reasons within Carnival’s exclusive
control, guests will have the opportunity to cancel their booking
without penalty prior to sailing and within 24 hours of the guest
notification, and in such an instance, guests will have the option to
receive either a cash refund or a future cruise credit. In the event a
guest does not cancel the cruise on a timely basis, no refund of any
kind will be available.
Due to the nature of a cruise vacation, itinerary changes sometimes
become necessary for safety, weather or other reasons beyond the
control of Carnival. If the itinerary change is for reasons beyond
Carnival’s exclusive control, including but not limited to safety,
security, weather, strikes, tides, hostilities, civil unrest, port
closings, emergency debarkations of guests or crew, late air, sea, car
or motor coach departures or arrivals, mechanical breakdowns or
problems not known to Carnival, itinerary changes consistent with U.S.
State Department travel warnings / advisories or other applicable US
or foreign governmental advisories, guests will not be provided any
compensation. Guests electing to cancel will be subject to the
standard cancellation terms.
ITINERARY CHANGE AFTER DEPARTURE
In the event an itinerary change becomes necessary while the ship is
at sea or when notice prior to sailing is not feasible, Carnival
and/or the Master will attempt to substitute an alternative port.
Carnival and/or the Master may, in their discretion and for any
purpose, deviate in any direction or for any purpose from the direct
or usual course, and omit or change any or all ports of calls, arrival
or departure times, with or without notice, for any reason whatsoever,
all such deviations being considered as forming part of and included
in the proposed voyage. Carnival shall have no liability for any
refund or other damages in such circumstances.
REFUND OF GOVERNMENT FEES AND TAXES:
If a port is cancelled from the scheduled itinerary, a refund of the
government fees and taxes for the cancelled port will be provided via
a shipboard credit.
THIRD PARTY COSTS RESULTING FROM CRUISE CANCELLATIONS OR ITINERARY
CHANGES:
Carnival shall not be liable to guests for any charges, fees or
expenses paid or owed to third parties by guests (such as air travel
booked by a guest directly with an airline) in connection with a
cancelled cruise or an itinerary change for any reason.