I created an AT5 map as described by "Hubert" in a previous topic:
http://reefmaster.com.au/index.php/forum/mapping/174-best-handheld-gps-for-icefishing-using-my-map#1532
For some reason it does not display in my Lowrance iFinderH2Oc. Can anyone help? Yes I am using the latest version of RM, the latest version of IMC and I have the latest firmware upgrade for my unit.

You will need to use LCM maps for the iFinder not AT5

There might be three mistakes:

- your unit does support only vector maps - no raster maps will work

- your unit does support only sd-cards with a limited storage space (maybe 2 GB / 500 mb?)

- your unit does support only at5 in older versions; I think it should be at5 version 7. you have to change this setting in IMC each time

Thank you Hubert. My problem was mistake number 3. I have the chart displayed in my unit now but for some reason the palette is different than what is displayed in RM. Have I missed something???

of course ;)

if you produce a vector map with RM, you have as standard the whole color palette HDS units could display.

Older units only can display a reduced number of colors. You can change this in RM. Go to 'global settings' - 'import/export' and in the last line use 'common' instead of 'indigo' or 'NOS'

With this setting you should get a palette, that is supported by your unit.
A good idea is to read the manual of the IMC; there are described the colors you could use for the different units.

Just to add to what Hubert has said, beware of the pre-made palettes in RM, as these will still be shown even if you change the global compatibility to something other than NOS, and may contain incompatible colours. The global colour compatibility only changes the colours that are available in the drop-down colour list, shown when either creating a palette or setting individual colours for areas in a user map. The most compatible built in AT5 palette we have is the one with white and two shades of blue. You might do better editing the depth colours in a user map yourself, but the options are rather limited on older units.

Thanks for all your help. Is there any chance that I can get bottom composition or am I pushing my luck?

On your unit? No reason why not, bottom composition areas are exported in the same way as depth areas, and there is no difference as far as the unit is concerned. You'll need to pick some compatible colours - shades of gray/black can work, but again there aren't many available for older units. What you might not get is switchable chart categores, which allows you to turn the BC layer on or off on the unit, but then again you might. You can certainly do it on some older units such as the LMS.

Just getting back to this as ice fishing season is fast approaching. Thanks to everyone for their help. I have everything working including bottom composition but I can't seem to import waypoints from RM into the unit. When I try to load "filename.usr" into the unit I get an error "User data file version is not compatible with the current unit software version" Am I doing something wrong? I am running the latest version of RM and the latest software version on my unit.

RM exports in usr 3 only, so perhaps this is not supported in your unit? What unit is it?
If you are running an HDS, try exporting in GPX format.

Matt

Edit: OK - I missed that you stated your unit at the top of the thread. I'm afraid that I am not familiar with the unit and don't know what formats it supports. By the sounds of it, it doesn't support USR3, but perhaps supports an earlier USR format? You could try using GPSBabel and converting your waypoints into an earlier USR version.

Thanks Matt. That's the ticket. Seems my unit is looking for usr version 2. Thanks again for all of your help.