Back to the use of a non-mapping unit. First you need to buy a
chart(s) from your resort for the resort for the section(s) of the lake that you will be fishing. The commercially available maps that I have found here in the U.S. claiming to have GPS coordinates don't offer much. The charts are very useful as they have Latitude and Longitude measures along the edges. I either find a spot the old fashioned way ( read chart, get in general area, then try to eliminate area until you find the spot). Once you are on a spot you can save the spot in your GPS and it will always be easy to return. What has worked better for me as I have gotten smarter ( and too lazy to spend time circling around until I stumble upon the spot) is to use a straight edge on my charts and calculate the Latitude and Longitude before I even go out on the water. That way you are a lot closer to the spot when you start your search. Again, when you are actually on the spot save over your original save and you got it. I number my spots on the map and in my GPS ( ie LOW 1, LOW 2, etc.)To be safe I keep two maps that are marked up with my spot numbers and I also keep a list of waypoints on my PC at home and carry an updated printout of my waypoint list to the lake with me. As Bob pointed out, losing waypoints that you worked to gather over a few years is a BUMMER. I hope this helps you decide which unit is right for you.