It all depends, how deep are you? In 20 feet of water, you’re reading roughly 6.5 feet of water at the bottom. So if you’re in a tight piece of structure, in 20 to 30 feet of water, I drill only about 5 paces apart. This let’s me see all the depth changes and be able to target most of the depths. If I’m on a basin searching for crappies, my holes are much further apart and I’ll utalize the transducer swing to help search for roaming fish.
FYI, if you’re running a Marcum on a 20 degree transducer you can figure out how much bottom you’re reading fairly simply by just taking 1/3 of the depth. So in 10 feet you’re only reading about 3.3 feet of bottom. You vexilar guys have to an equation to figure yours out! 1/2 of the cone angle x tan (depth of water) x 2
So vex guys for a standard 12 degree in 20 feet of water it’d be
6tan(20)2=4.4 feet of bottom in 20 feet of water (roughly a quarter of the depth)