If you get a broadband USB stick that works with Sprint and plug it into something like the Cradlepoint PHs300 you will have created a hotspot for the boat that can be used on anything and up to 5, perhaps more, computers, phones and pads. The reason for the Cradlepoint instead of a Myfi is that with something like the Cradlepoint hotspot that you can plug a USB broadband stick into it that can be used by any carrier if you decide to change.

Cradlepoint at Amazon http://www.amazon.com/dp/B001212ELY/ref=asc_df_B001212ELY1837559?smid=AGNVO1SI8BPQA&tag=hyprod-20&linkCode=asn&creative=395129&creativeASIN=B001212ELY

Sprint USB modem stick http://compare.ebay.com/like/320763107835?var=lv

My son works for M.S.C. and travels a lot through the Western Pacific. He has that system and says it works fine. He has a Sony USB modem that he can plug different SIM cards from different carriers into. He just keeps all the SIM cards in a bag and puts the local one in the modem, plugs the modem into the Cradlepoint hotspot and,, Budda bing, budda bang,,, online and wireless using Skype to talk to and see his daughter where ever he is.