I did some further research, being recommended by many to use Skype.. which would require buying a laptop, then paying Skype's rates to a land line or cell phone of 2.4-2.2 cents per minute (or less) for an international call. Even then I'd need to pay to use the onboard internet access fees. For example, Norwegian Cruise Line offers a package of 33 minutes for $25 - 75 cents a minute.. before I buy a laptop, pay for Skypes fees.. going over $3 a minute at least (before I consider the cost of a laptop).
If I use my own mobile I'll be subject to any roaming fees my mobile phone provider deems appropriate. Others had the same requirements for me to buy a laptop and pay for access per minute/data fees.
Fortunately I found that renting a satellite phone would be the cheapest option overall on board a cruise ship. I'd only have to pay a daily rental fee (than buying a laptop and then the Skype+internet access fees), and was more cost effective than the international roaming charge my cell provider was going to charge me (plus a charge to activate it) and then the additional cost per minute call charges.
The largest advantage of this is that I can use it from anywhere at all at exactly the same rate. While I can use the antenna extension to get access from the privacy of my own cabin I can freely walk around outside the ship calling home stress free. Plus I love to walk while I'm talking on the phone.
Further Reading:
Wikipedia List of Cruise Ships
$6.95 'economical' calls to Cruise Ships
