Hotmaps accuracy

[scrutch]

Before I go fishing I study a lake map to identify where I want to go (as most of you do I'm sure).  What I find is rampant inaccuracy with most of the maps I'm studying. 

I'm targeting the spring for a major electronics upgrade. 

I would like to know if any of you guys that have these Lakemaps Premium cards (or others) installed in your electronics notice how accurate they are.

If they're inaccurate, to what degree?

Is one card better than the others?

[Fishing Rhino]

I have the Navionics gold in my 898.  On the lakes they have charted in one foot increments, they are very accurate. 

But on the ponds and lakes that aren't charted, but are in the system, they are way off.  I've been a hundred yards from the beach and the icon of the boat shows as being a hundred yards on dry land.

The moral of this story is, do not depend on them solely for navigation purposes.  But, if you mark a honey hole on either of the maps, it will get you back to that spot with great accuracy, even if it appears to be on dry land.

The reason the charted maps are accurate is that they are based on recorded data from satellites, and depth readings, and are so plotted.  The others are apparently taken from generic maps from whatever source. 

Plus, the charted waters in the gold version also show roadbeds, creekbeds, tell you where there is submerged vegetation, standing timber, etc., on waters formed by dams such as those along the TVA.

[Long Mike]

I don't trust any of them when it comes to navigating any body of fresh water.  Water levels can fluctuate to the point of extreme danger.  Stay within the channel markers and keep your eyes wide open.  If out of the channel, I'm running 5mph max.  Bear in mind that many of the lakes I fish have standing timber.  In fact I am headed for a week-long fishing trip at Toledo Bend tomorrow morning.  The lake is seven feet below full pool.  There are tens of thousands of timber stick-ups.  Given this situation, would you trust your FHS or Navionics charts?

[R520dvx]

I think it depends on the body of water .... Navionics Premium and Platinum 2008 and after are pretty much right on for Kentucky Lake and Barkley ...

[Carrington]

i have the best navionics chip that i could find for the east coast lakes(forget the exact name of the chip).  The chip is very accurate, when it says im in 15 feet of water, its never off by more then 1 foot based on my depth finder. 

[Wayne P.]

The accuracy at a particular body of water is only as good as the map source. Even the HD maps with the 1' contours are way off at some locations because the survey crew does not chart every inch of shoreline to the deepest depth around the whole body of water. I know of several locations that a HD map shows a steep drop at the shore and it is actually a very gradual slope on a point. Most are 'generally" close but don't bet your equipment on their accuracy.

[Jig Man]

I have both brands in my units.  I find them to be right on in certain places in the lakes that I fish and way off in others.  Nav seems to be worse than Hot Spots for depth in open water flat areas.

[bowfish12]

I think it depends on the body of water .... Navionics Premium and Platinum 2008 and after are pretty much right on for Kentucky Lake and Barkley ...

x2. Major water ways are marked pretty good.  Still with the drawdown we have now I don't run out of marked channels on plane right now, excluding bays that I know from experience where to run.

[Carrington]

i know the bodies of water i run in very well so i will run on plain anywhere that is 5 feet or deeper.

[scrutch]

The accuracy at a particular body of water is only as good as the map source. Even the HD maps with the 1' contours are way off at some locations because the survey crew does not chart every inch of shoreline to the deepest depth around the whole body of water. I know of several locations that a HD map shows a steep drop at the shore and it is actually a very gradual slope on a point. Most are 'generally" close but don't bet your equipment on their accuracy.

This is exactly what I experience right now with a paper lake map.  I've marked a few steep drops close to a shallow flat where a creekbed and an old roadbed all converge.  When I got out there, it was a gentle slope to the road and creek, with no shallow flat.  No fish there, a total waste of time.

[Way2slow]

I just got back from Lake Falcon and have the newest Navionics Platinum. Like others have stated, it's only as good as when it was made or what data was available. Falcon is one of their high definition lakes but the lake was up approx 20 feet from when they made the map. We were catching large numbers of bass, that according to the map, were about a mile inland from the lakes edge. The map was however, still very helpful because we were able to see where the channels and road were, and way back in those is where we were hammering three to five pound bass for three days, don't have a clue how many we did catch. We didn't boat any big fish but did get a couple on, there was just way too much cover to pull them out of it. We were actaully using the roads to get through much of it because the brush/tree tops were just a thick mess sticking out of the water to go through/over when getting back in some areas just to get to the roads/power lines, etc.

As for the gps accuracy, even way back off the lake like we were, they were dead on. As we were going over where the roads were, it showed us being dead center of them.

[Catt]

As far as running boat lanes I have seen major inconsistencies, as far as reading structure they are pretty much dead on. 

[Way2slow]

I had just the opposite experience with tracking. When zoomed in on the HDS-10 and following our previous tracks, it was dead on, and I mean dead center. I was cutting paths through brush/tree tops as thick as hair on a dogs back. When I back tracked and followed the tracking path on the chart, it had me right on the path I had already made, which was very easy to see after the boat had plowed a path through the brush.

One thing I will note that was somewhat surprising to me, on all three HDS units, I had to go into the setup and turn on the WAAS capabilities, they do not come with it on.

[Wayne P.]

Way2slow, the track/trail is not any part of the mapping and will be as accurate as the unit's capability.

The mapping is an overlay on the plotter screen that the waypoints and tracks are shown whether a map is displayed or not. The mapping software is where some are experiencing errors.

Your post is the second one I have seen you mentioning a HDI unit. When did you get an HDI series unit? I've only seen or heard of HDS units by Lowrance.

[Way2slow]

Dam CRS Disease!!

OK,  HDS-10, thanks for keeping us old folks on track.  I guess I just came out with a new product line for Lowrance.

[Wayne P.]

I am old folks too, LOL

[northern basser]

I have a navionics premium for MN area and surrounding states.  Like mentioned earlier,  more popular lakes that are broken down to 1' increments the chip is very accurate.  Smaller less popular lakes(in MN there are all types)  it only breaks down to 5' increments and is not always exactly on.  All in all I'm pretty impressed w/ it.