Not long ago, cruises were a rare bastion of escape, where travelers could mostly duck mundane intrusions from work and home.

Deep-six that notion.

Miami-based Carnival Cruise Lines and top competitor Royal Caribbean Cruises International last month finished outfitting their fleets so passengers can use their own cellphones virtually anywhere onboard. They are among a host of cruise lines adding cellphone service, the latest technology offered at sea to connect passengers to land.

''You can send text messages and use your BlackBerry just like on land,'' says Carnival spokesman Vance Gulliksen.

''Some people really want to get away, and some people want to check with the kids and the office,'' says Gulliksen. "It's really a personal choice.''

The dilemma of cell service has provoked much hand wringing over how to balance the desire to get away with the need to stay connected, say cruise lines.

Passengers have gravitated to cable TV, Internet cafes and, most recently, WiFi Internet service, which was completed on Royal Caribbean ships last January. Cellphone service was ''the next logical step,'' says Chip Norcross, manager of onboard revenue for Royal Caribbean.

Norwegian Cruise Line became first to go fleetwide with the service in July. Celebrity Cruises is rolling it out now, with two of its nine ships complete.

''It's all about options,'' says Stewart Chiron, a cruise expert and president of Cruiseguy.com. "Cruise lines have to stay ahead of the curve as best as they can.''

The biggest player in the oceangoing niche is Miramar-based Wireless Maritime Services -- a joint venture between Cingular Wireless and Maritime Telecommunications Network, a satellite service. It has installed service on Norwegian Cruise Line, Carnival and Royal Caribbean, among others. While the Cingular venture operates the service, most cellphones will work, since the provider has agreements with carriers like T-Mobile and Verizon.

Calls aren't cheap. Cingular charges $2.49 a minute, and other carriers have their own rates. The cruise lines get a share of the revenue, though Cingular wouldn't give details.

Though pricey, it's still cheaper to use cellphones than cabin phones, where calls can cost $6.50 a minute or more.

The cruise lines fretted about onboard talkers annoying other guests, but so far, Gulliksen says, nobody has complained.

Veteran cruiser Jerome Cohen, a Hallandale executive who has carried a cellphone since the days when they were big and clunky, welcomes the service for his next Caribbean cruise in March. Last year, on a cruise along the east coast, he used his cell whenever he got near shore, he says, "but all of a sudden I'd be out of range, and it was frustrating.''

Cellphone chatter on board won't annoy him, says Cohen. ''When someone gets a phone call in a restaurant, I've never felt any resentment. Usually I reach for mine, thinking it's for me,'' he says. "Cellphones are part of what we are now.''

HOLD OUTS

Still, a few cruise lines are holding out.

Disney Cruise Line says it doesn't provide cellphone service and currently doesn't plan to. Spokesman Jason Lasecki says, however, customer demand will drive the decision. "If we see there is high demand, it's definitely something we would evaluate.''

And Princess Cruises, which caters to a mature crowd, has taken a cautious approach. Only in the last month or so, the upscale cruise line began testing cellular service on board the Grand Princess. Princess says it wants to assess the quality of service and the effect on ambience.

''We want to make sure it's going to be right for everyone on board -- those using it and those not using it,'' says Karen Candy, a Princess spokeswoman.

To surmount such hesitation, Wireless Maritime will provide ''quiet zones,'' where it blocks cellphone reception -- in theaters for instance.

Royal Caribbean says it has opted not to block ship areas such as restaurants and theaters but reminds guests to turn off phones or mute the ring.

To install service, Wireless Maritime dispatches technical crews on voyages, boarding them in crew quarters. Antennas the size of smoke detectors installed throughout the vessel link to the ship's satellite communications, which transmit a call to a satellite in the sky. It's then down linked onshore to the other phone.

SATELLITE SNAGS

Cingular says the biggest cause of dropped calls onboard is the link to the satellite in space, which may be momentarily interrupted as a ship prowls the seas. The satellite can also cause a split-second delay in reception.

Many folks who can't stand being out of touch at sea already use their laptops with VoIP, or Voice over Internet Protocol. On a recent voyage on the Norwegian Pearl, passengers used WiFi to check e-mail and Internet and to make phone calls, says Chiron. "One guy was sitting with his feet propped up, looking at the ocean, conducting business like he was in his office.''

Norcross, of Royal Caribbean, says cellphone service allows passengers to be reached on their regular phone numbers. Also, the phones will work in regions like Europe, where most U.S. cellphones aren't compatible with land-based cell service.

And the reach is wide. Orient Lines has added the cell service on a ship that sails to Antarctica.

''We take it as normal,'' says Leighton Carroll, chief executive officer of Wireless Maritime. "But it's pretty amazing when you think about it.''