There are few UK policies which would provide full cover for some of the amounts being quoted, even with including Cruise Cover options.
Cruise Cover extensions typically cover arriving too late to join the cruise at initial port of departure, cabin confinement in the event of illness, cruise interruption if you are taken ashore for medical reasons and unused excursions if you are ill.
The travel delay section of UK travel policies usually pays a fixed amount (typically less than 100GBP after a delay of 12 hours with additional smaller payments for every subsequent 12 hours) in the event of a delayed or cancelled flight etc.
The missed departure section is the one most likely to cover this scenario. They usually read something like this
You are covered up to the limit as shown on the Schedule of Cover for necessary hotel and travelling
expenses incurred in reaching Your booked destination, if You arrive too late to commence Your booked
trip from or to Your normal Country of Residence as a result of:
a. The Public Transport in which You are travelling is delayed (You must obtain written
confirmation from the transport company)
b. The vehicle in which You are travelling being involved in an accident or breakdown, or You
being delayed as a result of a major accident on a motorway. In the event of a claim due to
vehicle breakdown or a road accident, You must obtain a police or roadside assistance report
c. Adverse weather conditions making it impossible to travel to the outbound departure point in
Your normal Country of Residence