Not sure. I think that they did the best they could using old maps of the lake. You see the first maps that I collected back when the lake was first built in 1977 showed these fish attractors. They even further described them as Circular Tire Attractors or Rectangular Fish Attractors. Most were made out of big timber that had been cut down and stipped of it's limbs and wired together with big cables. I fished a few of these when they were new. The ones I fished were in shallow water and you could see the big logs under the water. Some of the deep ones I could not find. But that was before they used GPS.


I just think that they looked at the old maps and then put the symbols on the new digital maps as close as they could do by eye. Obviously it was not a very accurate way of putting in the fish attractors. To top it off when they digitized the paper FHS map of Patoka Lake they changed the name of these things from Fish Attractors to HAZARDS. Now people will avoid them thinking that it may sink their boats.

Best thing to do is get a better topo map of the lake. The Corp of engineers did a survey of the flood area before the lake's dam was complete. This aerial survey shows the land elevations in 5 ft contours. The FHS maps only show the elevations in 10ft contour lines and that does not show a lot of the details on the elevation changes. The 5 ft contour lines have some supplimental 2.5 ft contour lines (dashed lines). So with the highly detailed maps and a good WAAS enabled GPS one can pretty well find the fishing holes. But it takes a lot of work to get this system going. First off the maps are using one grid type system and the GPS units these days don't come with that grid system. Therefore a lot of math is required to turn the map coordinates from one grid system to another grid system that the gps units can use. That is very time consuming.

Just beware that the FHS maps of Patoka Lake have some inherrent inaccuracies. But they do pretty well show the river channel. I have used my Patoka Lake FHS map on my Garmin eTrax Vista and followed the old river channel by watching the small map display on the Vista unit. I only did this for a few spots but those that I checked showed the river channel pretty accurately.

I may check my Patoka Lake Digital Map by putting it on my main computer and then finding the exact coordinates of each of the hazards (fish attractors) shown on the map. Then when I am out on the lake I can go to those map coordinates and use the depth finder to see if the fish attractors are there where the map says they are suppose to be. I have a feeling that they are within a few hundred yards of where they are shown on the map. But they don't seem to be spot on.