I take my readings from the suface off of my dock making sure the water isn't shaded, then use my paddle wheel to get readings from the center of the pond.

.10 surface acre pond, 10.5 foot deep. SW LA. The epitome of a mutt pond. BG, LMB, GSF, RES, BH, Warmouth, Longear Sunfish, Gambusia,Mud Minnows, Crappie, and now shiners!!...I subscribe!!