Apps on Board: Navigation, GPS and Locational

Anyone have an app that works off phones GPS and without the need for internet or wifi while on board?? Looking for an Apple ios app that does this. Some recommendations in past have been Galileo Pro, BUT I am also looking for something more "nautical" that shows location and other ships in area too.

Thanks for help in advance.

I have tried the gps only but it wouldnt load the map. We went to Belize last year and i downloaded some maps. When we got to the port, i pulled up the map, flicked gps "On" and i had some navigation. I do think it would not be helpful if you want something to work while sailing. But you could use it off ship, in ports if you download the maps. I am referring to google maps....