Good app but charts are off – Wärtsilä iSailor Review

I've been using this app for the last month now I love the UI and the functionality. I use it for rec and fishing charts on iPad Air 2 in miami. Still wish it had a few more features but that anchor alarm is perfect I love to see a real sharp graphic of where I drift. Beats my gps for a millionth of the cost. But chart depths seem to be off from my other charts and avg readings. I boat in the bay a lot avg 5 to 12 ft deep but chart avg 1 to 6 ft. I guess that is better then the other way around. Just worries me sometimes in new areas when it states 0ft when I'm in 4 ft.i wonder if it's based on a deeper keel as I drive a 23 hydra sport and not a sailboat. If so would be nice in boat settings to be able to adjust that to reflect on charts .
Review by TheIrish33 on Wärtsilä iSailor.