It's called GPS Kit and it isn't made for water, however, I make it work. First it allows you to put waypoints in sets. I chose to start at Rodman Slough to Ceago Dock and labeled it Rodman to Ceago. Inside that set, I have 15 or 20 way points with descriptive names of places I fish.
Here's a small example of the waypoints in the map view.
I make all my way points in Google Earth and save them. They are backed up on two drives as all my data is. Then 1 by 1 I transfer the way points to GPS Kit. You can set them in GPS Kit but I prefer this because I have 200 entered and it's more accurate.
So, let's say I'm at Henderson and I want to go to Tule Island and I'm fogged in. I zoom in on Tule Island and touch the red pin and it identifies it and tells me how far away I am.
(the distance here isn't correct for Henderson, but it is for my house). If you then touch the > inside the blue circle this screen appears.
Then if you touch the compass the screen will change to this.
Once you exceed 4 mph the compass will turn in the correct direction and guide you to Tule Island. If you have the Track feature turned on it will save your track for later use. .
You can also email coordinate to your computer for putting into Google Earth at home.