You can accomplish this with a mi-fi. I did have to go to the Lime store and set it up but is works great. The guys at the Lime store were very knowledgeable and we set up a Long Overdue network. This is what we have on the boat:
http://www.ebay.com/itm/MiFi-2372-Unlock...=item5d4faf7cae

The data package was 3 gigs for $50. We were there a month and had a gig to spare