Standard Mapping chip

[cajun bill]

Friend just told me about Standard Mapping chips (also saw it in an old La. Sportsman). Looked online, but the website is kinda primitive. Anyone have experience with this? It appears that it will replace the OEM map provided by Navionics for the Lowrance Elite HDI, but since I already have a microchip in the unit, not sure if it will work correctly if I replace that chip with the SM chip. Just looking for input. I have some of the "paper" SM maps and they seems to much more current than my old maps so it intrigues me. Would also be nice to know that I'm actually running on water rather than the land shown on the Navionics maps on their chip.