Cardinal marks can help you learn which side of the mark you need to go. It use compass of your device to determine azimuth of the mark, with azimuth your relative position and direction that you must follow to safely avoid danger.
My test showed that build-in compasses are not very accurate, specially in sea condition on boat. You should always keep device in horizontal position with 'head' towards the mark and double check azimuth with real compass.
Sailing out on ship without knowing 'rules of the road' is very dangerous. Please use this nautical app, learn this small part of the rules and make your marine navigation bit safer.
This app is available on English and Croatian language.
Croatian name is Kardinalne oznake na moru.
Please visit my website for more nautical and sea related educational apps!
Many thanks to Denis Toić who let me test on his HTC :)
Thank you all for using and commenting this app!