Most prohibit "Ham Radios" and from talking to friends in the industry that was written for the HF side, not mean't for 2/220/440 etc. Scanners have been no problem, altho you might get questioned by Security if they do see it [even in your room - Stateroom Attendent might advise them]
Best to
a.) Carry on - vs Check any Radios [less Scrutiny] same with Laptop etc
b
Keep the Two Way hand-helds low key, altho FRS/GMRS are all around
c.) Scanners - use ear buds/head phones
d.) Leave the Radios on-board vs Shore Exc - you never know what the Laws on the Land are. I did use my 2meter HT in Bermuda a few years ago [they issue a Temp License]
Wirelessly posted (Mozilla/5.0 (X11; Linux i686; U; en-US) Gecko/20081217 Vision-Browser/8.1 301x200 LG VN530)
Check the cruise lines' website to see if they have any restrictions on scanners or 2-way radios. Also be aware that the laws in other countries regarding private possesion of 2-way and scanner radios may require a permit if you go ashore with it.