I went searching for reviews of the Navionics Mobile app an found a good one on the Kayak Fishing Mag site.
http://www.kayakfishingmagazine.net/...ne-review.html
It sold me. I plan to order this app today. Since I always carry my iPhone on the yak and don't currently have a GPS chart tracker, buying this app for around $10 seems like a no-brainier. Now I just have to hope that I don't drop the phone overboard while playing with my new toy.
Bob