Our regular chart plotter died on day 2 of our 3 week boating vacation on the West Coast of BC. We found and downloaded this app with the appropriate charts and were very pleased. Since we were travelling to unfamiliar destinations, this app worked great in plotting courses, recording tracks, and even estimating travel times and fuel consumption. Now that they have added some anchor alarms etc. it is even better. We paid well over a $100 for the same charts for our chart plotter so these charts are actually economical. You definitely need this at least as a back up. Worked great on the iPad and I understand that once you buy the charts you can use them on all of your devices. Side note, West Coast charts were restricted from downloading over cellular network directly to iphone due to their large size so we connected iPad to iPhone4 thru hotspot and downloaded it to iPad over "wifi". Worked great, downloaded in a just a few minutes and we were back on the go! This is my first recommended app.