Flytomap is a valid and interesting alternative, Benetti YachtsTop Ten 2011,2012,2013,2014,2015 & 2016Featured in : On the Deck London - Thames coverage resident in the app. It works WITHOUT mobile coverage! Worldwide Marine and Outdoor Maps available when connected, thanks to viewer.flytomap.com Worldwide Satellite images overlay on charts Worldwide Terrain features overlay on charts, thanks to Open Street Map, Open Cycle Map, Bing,Earth,GMap Worldwide Weather forecast Use to Explore: Latitudes and Longitudes to go to your favorite places Search your Favorite points directly Zoom, Rotate and Pan fast just by a finger touch Quick Object information just tapping, thanks to vector technology GPS Heading Vector Towards the direction movement Distance Measurement Tool to easily calculate the distance from one location to another Route planning, Waypoints - Insert the target/destination and see in real time your speed, distance and bearing Magnified Lens for all info Unlimited Tracks, Markers, Geo-tagged photos, records and share via email, visible on Google, Flytomap Viewer, KMZ format - Store your track without the need of cellular data or mobile signal Select Depth Contours a la carte menu iOS background mode - Flytomap works in background as well, you can swap with another app and receive/make calls send sms while track recording. Optimized battery usage And so much more to come - Its the only app you will ever need! Our charts are installed on: GARMIN NAVICO LOWRANCE B&G NORTHSTAR EAGLE SIMRADLearn more about Flytomap : www.flytomap.com and join us on Facebook or Twitter. Flytomap is committed to constant improvement, this App is developed with the help of professional boaters to get the best experience on the sea, we listen to our users and systematically add the most requested features. Thank you for the feedback!"Continued use of GPS running in the background can dramatically decrease battery life."