Lakemaster Accuracy ???- some comments

I recently purchased a Lakemaster Promap Mn chip for my Lowrance 3500C. I was very excited to use it on Mille Lacs for the Fall full moon trolling bite. Especially with the 1 foot contours.
I hesitate as I write this because I want to word it appropriately. I’m going to say I was mildly disappointed in the accuracy of the contours. For one, in the bays like Sha Bosh and St. Alban’s on the West side, the depths were off by a couple of feet. Now I know that water levels and my transducer being in the water a foot can play into that, so it wasn’t a super big deal. However, I fished Myr Mar a lot and we found tons of rock humps that would come up 2 or even 3 feet without showing up on the map at all. (And yes, I was zoomed in all the way.) In my opinion, humps like that might be the “spot on a spot” that we are all looking for.
In conclusion, If I were going to write a field report on it, I’d say that it definitely serves as a great tool to get you on and around a piece of structure, but don’t expect it to do all the work for you. There’s still a ton of stuff that it doesn’t show.

Good Fishin’
Crossin’

I thought it was a lot more accurate myself till I started hitting similar spots.Some places it is way off.Probably why they put the disclaimer on it.Still worth every penny tho.

Mike,

Even-though Mille Lacs and a few other Lakes have the 1′ contours they cannot account for a Spot on a Spot in all circumstances. We need to keep in mind that these Lakes are sonared from planes and based upon the waves that are bounced back to the plane is what determines the depth. The contours for the most part are pretty dang accurate and will get you close to large humps but not necessarily those small little humps. Also keep in mind Lat and Longs are constantly being altered w/in reason for the Nations safety.

Overall these maps have reduced the learning curve on any Lake by Years. I would highly recommend them to anyone.

LazyEyez

I was surprised by the differences I found from Dave’s Lakemaster chip to my Nav chip. I can’t say one is better than the other, but there were some noticeable inaccuries on both. Especially on Myr Mar!! That’s OK too. Now we can keep “our” spot a secret!!!

It is very good as long as you are in water deeper than 10′ to 12′. The way it was produced (I bought my Garmin 182 & chip in person from them in Little Falls) was to get on a contour and follow it. Shallow stuff is going to be off.

Actually, when they did the sonar survey to make the “ReelBottom” map of Mille Lacs, they did it entirely with a boat. Ron Westberg did the survey, and it took him almost 3 years to complete it. I understand that he used exsisting state mapping datum as a guide, but charted the whole lake himself, at least all the waters that his boat could float thru. He used a small cabin cruiser with a very suffisticated GPS/computer system which basically asigned a GPS coordinate to every sonar “ping”. When he was done, all the datum was converted to a map.

I am pretty sure the reason maybe you don’t see every 2-3′ hump might be because the water was too shallow for his survey boat (cruiser) to navigate, so he ended up depending on the state datum for those areas.

That said though, I was my understanding that LakeMaster did their own survey for their chip. So who really knows.

As a devote shallow water rock fisherman, I’m glad all MY spots aren’t on there for the rest of you guys to use!!

I kinda got a kick out of this….. I’m a dedicated lakemaster chip user. I’m glad I grew up in the greatest technology influx era. No offense to anyone but need we remember the times of checking depths with lead? Maybe in another 20 years we can criticize inaccuracies like this. But I agree it would be really nice to have it right on the nuts. But until then, I’m glad they haven’t found my rock piles. But I’m wondering about the Gps accuracies. We all know that its great to be accurate within 10 feet. So I’m wondering if we should criticize the Maps or the accuracy of our gps’. Some of the humps and change in depth could be greatly misinterpreted simply by that “Accuracy” of 10 to 20 feet you see on your screen.
Simply a theory

Hey Kooty Im still looking for that new mudflat you found this year.

I’m not saying I’m unhappy I spent the money. To get you “close” it can’t be beat. But this Spring when I asked on this forum how people liked them and how accurate they were, all I heard was how “incredibly accurate” they were. I guess maybe my expectaions were too high.
Mike, you are right, they will shorten a learning curve, but I feel like I know the “general layout” of Mille Lacs pretty well. At least on the Northern 2/3 of the lake. I was looking for “spot on a spot” accuracy that just wasn’t there.
I guess I just want people like myself to know what they are getting so they arent disappointed.

I think your looking for more than you should. First, I think this “one foot contours” should have some facts applied. The only place one foot contours would be accurate is on the line traversed. These are computer models, either side of this line the computer modeling program is guesstimating a value. What should be asked is how far apart the lines each company used for the survey. The closer the lines the more accurate they might be. Then it should be asked if they see any sturcture, do they stop and flow it.
I only do small lakes in the NE metro but any more my rule is lines no farther apart than 50 meters (150 ft), which if you want to picture it is to start at a passing stripe on the road and go to the third one up. From there if I see a break of more than 2 or 3 feet I break off the line and follow it perpendicular in both directions till I get to the other 50 meter line. And you know what? I still miss small rock piles, but I figure they’re less than 50 ft across, the distance from tip of one skip stripe to the next.
What you guys should be looking at is Doc’s classes on making your own maps with the SLG system by Lowrance. Then you and only you and who ever you shared it with would have that “perfect” map.
WarrenMN

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Hey Kooty Im still looking for that new mudflat you found this year.

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Great info Warren. I’d love to come take them, but then how do I get my hands on raw datum, what equipment do I have to have to collect the data?? As you know, most of us can’t afford to upgrade our graphs to the MMC or hard drive style. Thus we buy the Nav/Lakemaster chips. I’m not saying Doc’s classes aren’t worth the money, however for the weekend angler like myself, it’s hard to justify the expenditure.

I certainly came across wrong it anyone thinks I’m complaining about the chip. It has been worth the $200 I spent on it. My mistake was buying into the marketing material that 1ft contours meant they covered every foot of the lake.

Please elaborate what type of equipment a guy should be considering so when I’m ready to buy the next set of E’s I’m buying the “right” stuff.

Thanks!!

John

You can get the raw data with any Lowrance GPS/sonar unit that accepts a MMC using the log chart function. $80 for a mapping software to create the contour maps. The Lowrance School shows what can be done and how it is useful. I am planning a separate test class on using computer software for fishing which will be very detailed. Making your own maps is not very helpful when LakeMaster has already surveyed the lake but the ones they haven’t my maps are helpful.

Thanks Doc!! I assumed it had something to do with capturing the data while out fishing then manipulating after you get “home”. When I get the next boat and buy the E’s I’ll be sure I have the proper equipment to start doing this.

ttt