gps questions

[goose]

I am wanting some information on the sonar/gps units that are on the market. I have an older fishfinder with no gps and wondered how the gps part helped since I have never seen one in operation. Are the only benefits to keep from getting lost on a big body of water and being able to return to a certain stakebed or sunken Christmas trees? Also, how detailed and how much help are the Navionics, etc. maps on small inland lakes? Do fish cribs show up on these maps? Have they really taken their boat in to each of these lakes listed on the website and taken accurate soundings, or how do they get the topographic information on these maps? What are the best maps on the market for big bodies of water, like Lake Shelbyville in Illinois and the Chippewa Flowage in northwest Wisconsin?

[goose]

I am wanting some information on the sonar/gps units that are on the market. I have an older fishfinder with no gps and wondered how the gps part helped since I have never seen one in operation. Are the only benefits to keep from getting lost on a big body of water and being able to return to a certain stakebed or sunken Christmas trees? Also, how detailed and how much help are the Navionics, etc. maps on small inland lakes? Do fish cribs show up on these maps? Have they really taken their boat in to each of these lakes listed on the website and taken accurate soundings, or how do they get the topographic information on these maps? What are the best maps on the market for big bodies of water, like Lake Shelbyville in Illinois and the Chippewa Flowage in northwest Wisconsin?

I know that I asked quite a few questions on this post, and you don't have to answer them all, but even one or two would be helpful. Thanks.

[CrappiePappy]

you're not likely to get an answer within a few hours of posting. Give the members a day or two, at least. This forum is more specialized in subject matter, than state boards or the main board, so it isn't as likely to be visited by as many people, in a limited amount of time.

... cp

[CatFan]

The map chips are a great help on inland lakes. They show contours on the bottom, and the map tracks with the boat movement and the GPS shows a trail behind you so you can retrace your route. Some maps show brush, bottom type, fish attractors etc.. Really handy running on a lake that has shallow spots in the middle.

You can mark a waypoint that will get you back within 20 or 30 feet of a piece of structure.

[goose]

The map chips are a great help on inland lakes. They show contours on the bottom, and the map tracks with the boat movement and the GPS shows a trail behind you so you can retrace your route. Some maps show brush, bottom type, fish attractors etc.. Really handy running on a lake that has shallow spots in the middle.

You can mark a waypoint that will get you back within 20 or 30 feet of a piece of structure.

Thanks. That's some of the information I'm looking for. I guess that there is no website that would demonstrate how " the map tracks with the boat movement and the GPS shows a trail behind you". Are there any map samples on the internet that would show brush or fish attractors that you mention? I have seen the pictures of the side-imaging, but never any pictures of brush on a map. Thanks again.

[rockmike]

Go to the Humminbird or Lowrance sites and they have simulator programs that show what you can expect.

[osagemo]

Hey Goose, mine has helped a lot. I just went from a jon to an aluminum bass boat. This means I travel in unfamiliar water a lot. I bought a hot spots map and it is similiar to the paper one that WalMart sells. Two or three years ago I was at Truman lake staying at the Super 8 or whatever. There were 4 big boats there loaded with electronic gear. I started asking around and they said they were shooting the lake to update their maps, can't remember who they were with.

[CrappiePappy]

Thanks. That's some of the information I'm looking for. I guess that there is no website that would demonstrate how " the map tracks with the boat movement and the GPS shows a trail behind you". Are there any map samples on the internet that would show brush or fish attractors that you mention? I have seen the pictures of the side-imaging, but never any pictures of brush on a map. Thanks again.

most any good topographical map will show "brush" (timber, swamps, building foundations, roadbeds, etc) ... just check the map's legend to see what kind of marks on the map are indicative of brush. Now, they won't show "brush piles", or attractors placed by anglers ... unless those places are given to the map makers. Fish attractors placed by the state's Wildlife Dept or DNR will appear on some maps ... but, unless they're recent additions to the lake, or have been recently added to, most likely they won't have much cover left. And in a lot of instances, the marker buoys aren't even there, anymore.

Look on the specific depth finder brand's websites, usually under tutorials or sample pictures, for the GPS tracking info & trails marking, etc.

Most topo (paper) maps are made from Geological Survey map info, I believe ... but KY Hydrografix maps are maps that are produced by combining flyover, depth sounding, side imaging, and topo information. Check here : http://www.kentuckyhydrografx.com/ and see what the latest in lake map creation is headed towards.

... cp

[osagemo]

When I bought my Lowrance 334 I was in Bass pro looking at them. I ask about a hot spots map which the clerk promply opened and plugged in to the 334 on display. I got to play with it a little before buying one.

[frank lawhead]

Goose the gps will take you back to the spots you find but the maps don,t show the brush piles [shelbyville has a zillon of them ] put there by people who don,t like to share them
but if you use the maps to find ledges and drops you,ll find a lot of them with your sonor [thats why people are buying SI sonors]