I own 3 chips (LM WI, LM MN, and Nav) and I use all 3 in different situations. Pool 4 is “surveyed” water on both the Lakemaster and Navionics chips. It is imporant to keep in mind that the river is ever-changing, so the information on the chips should be considered a good guess, but certainly not the bottom line in accuracy. I can think of well over a handful of places on P4 that aren’t even close on my Lakemaster chip….I can say the same for the navionics chip.
As Brian stated, an advantage of the lakemastger chips is that you can zoom in much closer on a Lowrance unit than you can for the Navionics chip.