Soz only got iPhone can't copy and paste the link 

google navionics sonarphone 

Would someone paste the link pls

Once they get a better ducer than a suction cup mounted one...

for A little more than the  price of a navionics platinum card u could have a cheap iPad/ tablet with navionics app. Add transmitter /ducer. Bingo

wonder if airmar gonna start making proper ducers for it