MGx3 12v 55lb variable speed bow mount. Have not tried it on continous/constant--only on intermittent. Never noticed it in shallow water (>8')even tho it was there. It was just a little snow in the bottom part of the screen that I probably thought was thermo or something. When I moved to a deeper lake it became evident. Once deeper than 16' it is very noticeable. Spikes when turning on, noise in bottom portion of screen while on--but not bad. Spikes (noticeable after 8') were what got my attention.. I am in a jon boat and have thought of an alternate method of deploying the ducer just to get it away from the TM. Not my first choice. What I have seen work before is not helping this time.