Taking Cunard as an example, by the time they get going again, it is now certain they'll have spent well over a year idling and without any maintenance that can't be done while either at anchor or in a brief day in port.
Are they going to be able to resume cruising from lay-up, and if not, what's required?
Not too long ago, Disney sent their entire fleet (4 ships - and the first time they'd all been together in one place) to the shipyard in Brest with at least some of the fleet spending time in drydock. The Disney ships that went into drydock didn't spend that long there either if I recall correctly. I suspect the likes of the P&O, Cunard fleets etc will follow as part of the logistical nightmare of returning to operation.
The drydockings will probably be minimal affairs to sort out essential things as Andy has mentioned, also including any regulatory/surveyor stuff, given the financial situations for each company particularly ones such as Carnival Corp which are not diversified unlike Fred Olsen although I think all the companies involved in the industry are feeling the pinch to some degree or another. Also they won't be able to spend too long in drydock given the unprecedented (from the cruise industry at least) pretty sudden demand for drydock space I would imagine.
Carnival Corp will complete its already underway refits such as of Carnival Victory into Carnival Radiance (they've confirmed as such) but I don't think any major refits or rebuilds (QM2 mid-life?) will happen for several years to come whilst the industry gradually recovers.
I gather QM2 is coming up for her next refit given the 5 year refit cycle Cunard currently have - which leaves things to be desired in normal times let alone now. QM2's boot topping has been in major need of tidying up in the past between the ever increasing time between drydockings, not to mention that several years ago one of the rubber mounts of her diesels had perished/deteriorated to the point that it wasn't doing it's job a couple of years out from her last major refit (when I gather it was finally sorted out). What sort of things like that are there that should or would need to be taken care of and will those sorts of things (not necessarily critical to the operation and safety of the ship) actually be dealt with particularly in the current state of the industry and in the rush to get going again ASAP?
Have the cruise ships shut off their plumbing and other systems in large areas onboard to save power and in turn save fuel? The issues with turning those systems on again might be there along the lines of the "Niagara" calls QE2 had.
Will the returning hotel crew have to deep clean large parts of the ships not occupied for over a year by that time - and how were those parts of the ships secured back then anyway? What COVID arrangements will have to be installed or put in place if they haven't been already?
Will regular maintenance and upkeep, numbers of crew such as for the waiting staff (which has been reduced over the years anyway, menu options (reduced anyway over the years) etc etc all be affected by less money flowing about or will it not be as severe as that?
Will we see a Cunard running on a shoestring budget for a time like they did in the last years of their independence but still taking on the as yet unnamed new ship whilst brand and parent company get back on their feet slowly but surely? Or will they bounce back quite quickly as part of the industry seeing something akin to a post-war boom? I suppose this partly depends on the success of the vaccines and the likes of the CDC allowing things to really get going again at least in a sustainable manner - all still up in the air and unknown at the moment...
