Suggestions for Marine GPS on Iphone 3GS

[santuitman]

Hello
I've got a iphone and was tyhinking that it has a gps so ther must be some good marine apps for it. I won't be able to try any til spring but didn't know if anyone had any recommendations. So far I was looking at both


motionX GPS
http://www.motionx.com/faq/motionx-gps/

and

flytomap
http://www.flytomap.com/ftm/index.aspx

Thanks in advance
Brian