DRx-10 Depth Raider - $449.99

The DRx-10 measures speed and temperature at the lure so you can find thermoclines and temperature breaks while adjusting trolling speeds for the most productive lure presentations. Displays speeds for 0 to 9.9 mph and temperature from 32F to 99.9F Features user-selectable temperature (F or C) and speed (mph, Kph, Knots). Large, easy-to-read LCD display. Probe runs up to 225 hours on a 9-volt battery (not included). Automatically shuts off when out of the water. - $449.99