Hi folks. I'm pretty new to Reefmaster, but very experienced with mapping lake bottoms. Used Humminbird AutoChart a lot up until this point, and with switching to Lowrance comes switching to Reefmaster also.

Anyways, I've imported all my Humminbird sonar recordings and track logs into Reefmaster, and have gone through most of my data.

I've created a 'Map Project', even several 'Map Projects'. I've noticed that if I make the 'defined area' too large for a 'Map Project', that it will take forever to triangulate the data and generate contours, and sometimes even crash before completing. So, I've read some more, and sounds like the better approach is to split the lake up into several 'Map Projects', and piece them together as a 'User Map'.

What I'm wondering is this:
1.) Is that the correct approach for a really big lake?
2.) How do you make the contour lines match up from multiple 'Map Projects' in the 'User Map', like where two 'Map Projects' overlap or join together?
3.) In the 'User Map', is there a way to merge the contour lines/isobaths where they meet from 2 or more 'Map Projects'?

How big is your lake?
The split & recombine approach can work, but at the moment we don't have a nice way of merging the results - so there will always be a visible join. This is something that we are actively working to improve at the moment, but that is still some way from release.

Overall, the lake is HUGE (231 miles long, and broken up by tons of bays and islands). It's a lake in Ontario that we visit each summer for a week. I've been collecting data for 1 week over about 4 years now. Obviously not mapping everything about the lake, just the areas we fish each year. However, that still leaves a huge area to cover. I drew a rectangular polygon around the areas that it would need to cover, and the rectangular area is 120 square miles. A good amount of that is shoreline, but you get the idea.
I can certainly tolerate some small overlaps/visible joins, and can use geographical features such as a narrow channel between lakes/bays to make the overlap less noticeable. I just wasn't sure if there was a better way, since I'm a new user to the software.

My lake is 80 miles long and 1-3 miles across, and I have to make 5 separate projects and put them on 5 separate sd cards.

You are doing it right, and if you match up the Projects close enough the lap between them is nearly impossible to see unless you zoom waaaay in. I mark the limits for each project with waypoints in a certain colour so it is easier to adjust the limits and since these waypoints show up when looking at each sonarlog it is also easy to see wich project each log needs to be added to.

You can use the same boundaries in all the projects, and then remove the surplus ones in the User Map. For my large lakes I have the same shoreline in all projects, and then add the islands to each project. That way I only have to delete the surplus shorlines from the User Map and save some time.

TJ wrote:
You need to rethink. :)
First off there is no need for several cards, you can have all your maps on one card. Put them in seperate folders, name the folders and you can then change the settings in your HDS in order to view each map. Second, if you use the User Map as i discribed in my post above you can merge those five maps into one. It takes some time to set it up in RM bt it is worth it and then some.

Team Colibri,
Thanks for the information. Sounds like I'm using the correct approach, which is good. As you mentioned, there are ways to divide the lake into several different project maps, and by adjusting areas where those project maps meet up with one another, those areas can be made less noticeable in the User Map.
For example, I can have the project map defined areas just barely overlap. If possible, I can use narrow geographic features such as a narrow channel from the main lake to the attached lake.

One thing you mentioned about the 'map boundaries' (shorelines/islands). I read on another topic, that instead of clicking 'Add all components to User Map' when in the Project Map view, that I could just click 'Add Contours', and then 'Add Isobaths', and not add the shorelines. I could just add the shorelines from ONE of my map projects that contain them all. That way I still have all the shorelines and islands in each of the Map Projects, but I wouldn't end up with multiple of copies of each island/shoreline that I would then have to delete in the user map.

Thanks for the help! Hope to have some examples of my progress to show soon.

That will work to. :)

Here is one of my maps buildt this way. You can see where two projects are meeting eachother if you zoom in far enough. This lake is 140 km2, and I have divided it into two projects. I could get the seam even less visible if I took the time to align my two projects more.