My Lowrance Elite 5 HDI has one micro SD card slot.
So, when I record on the water, I am recording to that micro SD card.
Now, if I had a unit with NMEA 0183 data collection, I could save the data that way (live) to an external device (laptop, ipad, etc)---at least that's my understanding, but I haven't explored this (no way am I bringing a laptop onto my kayak)
With Lowrance units, the set up is just about identical to using Insight Genesis--you go through the same initial process
1. Turn on unit and make sure you have GPS signal lock
2. Get to a page with chart view on the left and 200Hz on the right
3. Go to menu and name a new trail (saving tracks and GPS data)
4. Highlight the 200Hz screen (press page button twice)--orange rectangle will now be around the 200Hz part of the screen
5. Press menu and select sonar logging
6. Name and save the name for the log
7. select start sonar logging
8. At the end of the day, go to menu, select sonar logging, and stop sonar logging.
The above is my interpretation of how to do it. I'll post a link to the Reefmaster manual below. Open up the "Importing GPS data" chapter and then select "Collecting Track Log Data" Reefmaster manual