Depthmate Portable Sounder Anchoring security for cruising sailors! Find deep water easily from your dinghy. Its signal is at 200 Khz, and has a 24-degree angle. The range is from 1.8 feet to 240 feet (0.6 to 79m). Each reading is backlit and the value stays displayed for about ten seconds. Waterproof to 150 feet (46m) and it Floats. Weigh 10.6 ounces (300gr) and measures 7.7 x 1.7 inches (198x42mm) with a standard 9V dry cell battery (good for about 500 readings).