just caught up with this thread!
ram mounts are excellent, we have the ball fittings all over the boat and lock down the iPad (and Bluetooth speakers) wherever we want for whatever use we're putting it to. it seemed false economy to buy an expensive piece of kit without buying a means to secure it securely on a moving boat! They also do holders that work with the mount system for loads of equipment including laptops. probably the best set of gadgets we've bought for the boat.
No one seems to have mentioned Garmin Bluecharts App? late 2012 garmin offered this which was what prompted our iPad purchase. NZ to off the coast of Brazil for 49.99£, fully integrated with Active Captain, and can talk to Garmin Bluechart plotters ( we don't have one)
This is our back up to our laptop running opencpn. Disadvantage is the two systems can't talk to each other to upload waypoints, they are completely separate. Suppose that could be an advantage too! Stores routes, photos, naming of waypoints, shows local information from offline active captain database.
Re GPS. We opted for Wifi and cellular iPad so we can use the personal hotspot facility to give all our laptops wifi access to the Internet. but I am still under the impression that the iPad uses a cellular signal (a sim that hasn't any credit works) to triangulate its position. Which is fine if you're within cellular range, but is it accurate? For this reason, We bought a bluetooth GPS to receive satellite data. Chose Dual because unlike the garmin (December 2012) Dual has a dedicated iPad app to monitor signal accuracy and battery. Also comes with non slip and wrist holders.
As far as I understand it, you don't need the wifi or cellular versions if you have a Bluetooth GPS linked to the ipad as you'd be able to navigate using satellite. anyone know differently?