Lakemaster map chip - problem lake?

[Fawkinnae]

I have a new Lakemaster map chip. I just started using it this spring and I haven't been on that many lakes yet. I used it on Winny for opener and was amazed at how accurate it was. Tuesday night I was on Clearwater - a lake you need a good map on if ever there was one. The map seemed way off. I'm wondering if any one else has had that experience on Clearwater or other lakes? Or, if there is some variable related to the satelites on a particular day or some other nutty thing? Another weird thing - it took my GPS 2 hours to lock onto our position???
Any thoughts or comments?

[Joe]

Ya that lake goes from 30 fow to 2 fow in a snap of a finger. Scared the crap out of me the first time I was on it. Anyways, How did you establish the way points in the first place?

[Fawkinnae]

Hi Joe
Well the beauty of that system is that you show up as an icon positioned on the lake map. On Winny I was always within a foot (depth wise) of what the map told me the depth was. On Clearwater frequently I was off by 10 or 15 feet in depth - which like you said is freaky on that crazy lake.