MacSailing.net

I found this a while back. It might be helpful for those wishing to get communications at sea on their Mac..

http://www.hintz.org/iridium/

Others have been using Skymate with Virtual PC with success.

I did an Atlantic crossing last year E to W, and did email all the way with Iridium and G4 PBook. If anyone has difficulties configuring, I'm happy to share.
Never let me down