I watched someone using one on the Providence River about a month ago. He would cast it out and then watch the monitor,he would have to retrieve it until it was about 40 ft. from shore before he would get any readings. He said it was supposed to be able to pick up and transmit data from 100 ft. The sensor was very light and ended up back on the edge of the river in a very short time. It was feeding back depth/fish info,and was entertaining to watch,problem for me was I stopped fishing to watch.......(for about 5 mins)he spent the next hour casting it and watching the data,I spent that hour hooking up, further down river.He was outdoors and having fun
