To ensure quick uploads and prevent file corruption, makers of C-MAP Genesis custom lake maps you can record several smaller sonar-log files while on the water, then merge those logs later into a master lake map. 
Depending on the size of the lake, creek arm or river section you’re mapping, you can create a complete, custom contour map from multiple sonar logs recorded in a single day or over multiple days, and with no complicated computer programming required by you – C-MAP Genesis’ innovative Cloud-based processors do all the work. That’s one of the many benefits of a Genesis Edge subscription over a free account. Other benefits include custom bottom-hardness and vegetation-location maps. (Blog post continues after images below)
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Follow these easy steps to merge multiple sonar log files into a master map:
- Log into your account at www.genesismaps.com.
- After logging in you’ll be taken to “My Data Dashboard.”
- On the Dashboard you’ll see the list of your “Genesis Trips.”
- Click on the up arrow (^) to the left of the waterbody name to see the associated trips.
- Select a waterbody from the list that has multiple trips. Click on the blue “View Trip” button to view the trip in the Trip Viewer screen. This action will open a new tab in your web browser.
- From the new Tab / Trip Viewer, click on the Tools tab on the left side of the screen and select “Merge Trips.”
- The Merge menu box will appear in the center of Trip Viewer. In the menu you’ll see the list of all the trips associated with the waterbody in order by date. (see image below).
- Select the Trips you want to merge by clicking on the box to the left the Trip title.
- You also have the option to adjust the Track Buffer size. The default buffer size is 25.
- Once you have selected the trips you want to merge click on the “Merge Trips” button.
- The Merge Trip Policy notification will open, if you agree with the policy click on the Merge button, otherwise click Cancel to stop the merge process.
- Watch your email in-box. You’ll receive an email when the Genesis processors are done merging your data into a single, custom map.
- To view the merge go back to “My Data Dashboard” and you will see in a column called “Genesis Merges.” click on it to view the list of waterbodies with merges.
- Click on the up arrow (^) to view the merge(s) associated with the waterbody and click on the “View Trip” button to see the merge in the Trip Viewer.
- In the upper left hand corner you can view the trips in a merge by clicking on the down arrow (v) to the right of the trip name in the upper left hand corner. (see image below)
Upload speeds depend on sonar log size and your Internet connection speed. Map-creation speed is based on the size of your logs files and total data size. The size of the water body might also be a factor. Recording multiple, smaller sonar-log files can provide better results, especially for Genesis users with slower Internet connection speeds. Click over to this blog post for tips for recording smaller sonar-log files.
C-MAP Fishing 
Big limitation is It only lets me merge a maximum of 12 trips to for a map. How do I merge a bigger area?
Tim: To merge more than 12 trips into a master map, you’ll want to upgrade from a free account to a Premium account. A Premium account will also give you bottom-hardness and submerged vegetation-location map layers — very powerful tools for identifying and expanding on successful patterns.
Can I download multiple water bodies onto a single micro SD card with my premium edge account?
Yes! Save each lake’s downloaded files into a separate folder on your computer, and then save all the separate folders to your SD card.
Can I merge my maps with a social map, if so how?
personally made custom map merges cannot be merged with Social Map charts.
Sure, just pay a small $100.00 fee for premium that last a whole year. then you get to pay another $100.00 fee when that expires. isn’t that wonderful
Jason — If in the first year of the Genesis Edge service you survey and create maps of all the waterbodies or areas on waterbodies that you are interested in, you would not need to subscribe for additional years (and thus incur additional charges). The maps that you create during the year of your subscription are not dependent on having an indefinite subscription — meaning, the maps will continue to work after you no longer have a subscription. — Greg
if I’ll want to upgrade from a free account to a Premium account I can upload and merge old sonar logs with a date before the date of upgrade?
Yes
Are both legacy sonar trips and the new sonar trips dated 2018 (already uploaded) available to merge into a single map with an upgrade to the premium version?
Yes
Hi Greg I have about 19 hours of the same water body uploaded to my Insight subscription now so the merge files are stating to get bigger and take longer to process, Do I have to merge the whole lot each time to create a new merge (which I dont think will scale to our water body or can I just add the new ones. Also how does the merge relate to the map generated if at all
Best Wishes
Mark
Mark, any time you record new files on the same waterbody and want to add them to create a more-complete map of the waterbody, you must create a new merge that includes all your files. Unfortunately, the process that enables you to merge trips into a map does not work in a way that new trips can simply be added to an existing merge. — Regards, Greg Huff
Hi, last year I uploaded log files with a free account and added them to the social map. Now I’ve upgraded to a premium account and uploaded some new files from the same waterbody. The old files were not shown to merge them into my personal map, even after trying to upolad them again. What do I need to do to create a private map which include all the log files I created. Many Thanks and Best Regards
Guido
Guido, sorry I missed this message earlier. Are you still experiencing the same issues? If so, message back and we can try to figure it out. — Greg
Hi, I am also experiencing the same issue. I now have a premium account and am not able to view my uploads from when I was using a free account. Also I do not have the old uploads to try to re-upload.
Can I merge 2 files if I only have the free version?
With the free version, your method for merging your files is via upload to the Social Map.
I want to create a high resolution map of a tidal area. (Alameda Estuary)
How do I account for the different state(s) of tide with multiple files at different times?
is there an ability to enter the tide level that the file was taken at ?
I don’t mind adjusting the values of the depths in Excel or similar tool if that’s what’s most appropriate.
Presumably they should be referenced to MLLW?
Trips are automatically offset for tide levels. You can also add manual offset from the Offset tab in the trip viewer.
We cant choose the resolution of merge maps , there is a big diference resolutions of merge maps with log sonars before and after 2018. Im dissapointed
If I pay for a year to create my own maps and then don’t subscribe the following year do my private maps become public?
No, they will not become public if your subscription expires. Private sonar logs will remain private unless it is requested by the user to make them public.
If I map a private lake that hasn’t been mapped and want to keep my maps private, I’m assuming that I’ll need a premium membership and I’ll need to continually renew it, as they will become social maps once I don’t renew. Is this correct?
No, they will not get added to Social Map if your subscription expires. Private sonar logs will remain private unless it is requested by the user to make them public.
Can you view a Navionic plus card and the private downloaded map i created on a split screen with both cards in each slot of my HDS 12 gen 3
Hi Bill – Indeed! Just create the split chart screen as you describe and select the chart source you would like displayed on both charts.
Ive merged 2 different bodies of water , i would like to be able to view them again , but when I go to view the merged maps it won’t let me look at my sonar .
Thanks
Can the track buffer be changed on a merged map? I’ve tried to make maps, using the same merges but with different buffer track size. I get an error message saying that a merge already exists with similar trips.
Yes the merge buffer can be changed. In the merge menu that appears in the upper right hand corner you’ll see the option to change the buffer.
After I download the map created by cmap and load it onto my graph (Elite Fs) do I or can I insert the cmap Chip I purchased (cmap reveal north central states) and merge it with that? I hope so
Sorry but you can only have map data set showing at a time. It is a good suggestion. Thank you.
So I only see the area I mapped. Or does it sync with other community maps of the area before I download it. I would fill in the gaps on the map I purchased if so . a more complete map would then be available to all.
If it is a private trip only your trip will show up. If you added your trip to Social Map, your trip and other users that contributed to the Social Map for that waterbody will be in the AT5 that you download.
Cool. I’ll give it a go