I personally have never used one but on the last cruise that I went on in March I remember seeing one gentleman a few times on the upper deck talking on a sat phone. It didn't seem that he was having any problems with the connection....his conversation sounded pretty steady without any "can you hear me now?".......after all it is working off of a satellite. I would say as long as it's cheaper than using the ship's phone then by all means rent one. Good luck and enjoy yourself.