Here’s how I do it. I bring my Helix 7 when I go to lakes where I know I’m going to need accurate mapping or it’s my first time out there, because honestly the mobile Navionics is no where near accurate on many lakes. If it’s a lake I know well, or am fishing shallow, I’m using the Vex.
Sometimes I even bring both……
Not meaning to jack your thread, but just wanted to share/add an experience I had with Lakemaster mapping on my Helix last week.
Went to a lake I hadn’t fished in twenty years. Studied a Navionics map and picked a spot with a 5-15ft dropoff I wanted to ice fish at night after work for walleye. Drove on the lake with my Helix/Lakemaster map to the edge of a 20ft contour. (Remember the Navionics map showed 15ft) jumped out of the truck and drilled a hole-right into the bottom! Moved 20yds drill another-again into the bottom.
Asked a nearby fisherman “if and where is there a 20ft depth?” “Not here” as he showed me an ‘off the wall’ contour map on his phone, showing 3-10ft deep in that area.
Just pointing out no matter how much we trust in technology and mapping, they are NOT always accurate. ;(