shallow water is one of the few times you want to keep noise to a minimum. in the depths you're talking about you can absolutely spook fish.
also try fishing on overcast days, this will help you be a bit more stealthy in that the sun won't shine like a spotlight through your hole, and you also won't cast a shadow that may spook fish.
if you ARE fishing a sunny day, consider bringing a shelter. fish don't mind a very large shadow that doesn't move, and may even be attracted to it.
if your water clarity is even somewhat decent, you could even skip the electronics and just sight-fish through the hole.