Partner and I made our weekly West Point trip tuesday . Put in at Ringers and head up river. Around 11 am we saw some strange deep V metal boats around Potato and New River. About every 15 minutes we'd see another one. Saw 4 of them just while sitting on brush pile. They are big heavy boats, with windshields! Went back to Ringers to take out around 3 pm. Got flagged down by a broken pontoon boat, pulled him back to the shore at Ringers. That big metal was pulling out. Talked to him in the parking lot. They are the Humminbird mapping crew. Six boats map entire lake from Brush Creek to the damm, in 6,7 days. Said he got stuck in New River 3 times, had to call for help. Also said he made it as far to where he could see the bridge. Should have taken pic of the boat. One-fifty Yam., had to be at least 21 foot boat, was not a Crestliner, no markings on boat or truck, Minn plates on trailer and truck. Young nice guy with a lot of stories. Yes he said they have to replace lower units regularly