I use an iPad on the boat with the navionics app, and it works great. The only downsides I have is it is not as easy to mark locations, and if your in direct sunlight it can be hard to see. Under the hardtop it is not a problem. I have a lifeproof case for dealing moisture. As far as gps location it is not a problem, you do not need to be connected to anything to receive gps location. Majority of the time I have my iPad in airplane mode, and never lose location even under the hardtop. Sent from my iPhone using Tapatalk