I have navionics on my iphone and could not be happier. I made a trip from Kentucky to Tarpin Springs Fl and it was the only GPS on the boat. The only problem was it slowed down when out of cell phone range crossing the Gulf. My 28 single

made the trip fine but a little rough at times.
I put the boat in a stack at Tarpin Springs and plan to go back and tour FL in Jan. and Feb. Hope I can run into some Marinete owners while down there. My boats name is Little Toot which was very fitting in the big water.
Again I would recomend the navionics app to anyone. I wish they sold the same app for a PC but I understand it is a lot more complicated where the app is a simple download and only $9.99. Anyone who has experience with navionicn on the PC I would be interested is knowning more information.
John