All the major cruise lines do not allow crew and staff to use mobile telephones while on duty or in public areas.
Off duty and in crew areas ONLY.
Violating this rule can find you unemployed rather quickly.
On my line - all the tech staff have 'dect phones' that are part of the ships system to communicate with. Our older ships have a pager system. Don't recall if the Sun even had pagers . . . you'll either be in your venues, the mess or your room - so you'll be easy to find ;-)
Most likely your cell might not work anyway when at sea, unless the ship has a satellite for this - and even then it's pretty expensive (around $3/minute). There are phone cards/sim cards/internet cards that can be used on the satellite system sold in the crew area to keep in touch with home.
AT&T seems to work better in most of the Caribbean ports, but if not a US territory or mainland, can be expensive.
This a technology that some cordless phones use . To explain this a technology that is used on home wireless aka cordless phones for home use. Each brand and/or implements
this in its own way. To see Dect just go to Radio Shack or Staples and look in the cordless phone section.
SS Ithaca , Volendam , Mariner of the Seas (x2) , Veendam , Coral Princess , Island Princess (x3) , Emerald Princess,Sapphire Sapphire (x3),Diamond Princess
the dect phone .. at least on RCCL ships . . is a closed system. You get a phone as part of your job/position. Most cruise ships have a cell tower that anyone has access to . . at a price. The company Oceanphone (and I'm sure others) sells phone service from guest/crew cabins and via phone cards in crew area or now sim cards for phones (that is accessed via a hard wired ship phone or cell tower)
Yaka - if nothing's changed at NCL . . you won't be able to use your phone (and I'd really not recommend it for reasons Bruce mentioned) at least in guest areas.
When you go to work on ships, you kinda go into a culture/communication bubble . .you'll understand once you're on