Hey Marc- Autochart & Autochart Pro would be ideal for Canadian waters that don't have detailed Navionics coverage. Seems that with the Zero Line SD card the more time you spend on a body of water, the more detail your own personalized map will include. Humminbird's press release states "Anglers now have the ability to chart private, public and hard-to-reach waters far off the radar of DNR surveys and commercially available paper maps and digital GPS charts. That means you can finally map your own favorite lakes, reservoirs, farm ponds, ever-changing rivers—even off-the-grid Canadian waters." Lakemaster, HB & MK are all owned by Johnson Marine Electronics so a Lakemaster card would definitely work in your 788c. Without a SI unit, one of the key benefits of Autochart Pro ( Merge Side Imaging Mosaic data onto the map for 3D visualization of fish-holding habitat -- the ultimate in coverage ) would be lost - although you would still have satellite image overlay & bottom hardness (very cool).

Lakemaster chart for ALL of Lake Erie & St Clair shows incredible detail in 1' contours & the little case the card comes in can hold up to 4 SD cards so it keeps me from misplacing (losing) other cards. I've heard that Lakemaster is busy charting lots of new water (for them) & that may include some Canadian stuff - but that info is rumour until/if it happens.