I confirmed that the sailer I know does use the IPAD with INAVx. I am still trying to verify if and what external antena he uses and which waterproof case. I will be purchasing the Ipad as soon as the new version is released, rumor has it this April. Then, using it as a GPS for both my boat and when I fly. I have been able to find external antena's in my aviation searches but not in my marine searches. I am assuming that the same one will work well for both. I wish I were more technical, cause it seems really cool. The link is not in English, so it was difficult to follow his trek across the atlantic.