The best fish finders for kayaks must be light, easy to mount, waterproof and durable. Because paddlers self-propel their kayaks, any extra weight added to the kayak means more work, so lighter finders mean less work. With limited deck space, anglers need a fish finder that is easy to mount. Anything mounted on top of a kayak gets beat up and soaked, so any electronics mounted to the deck need to be waterproof and durable. A fifth desirable feature is a built-in battery. A built-in battery prevents extra wiring and extra holes from being drilled through the deck---only one of the following fish finders, the Garmin, requires an external battery.
Eagle Cuda 168
Completely sealed and waterproof, the Eagle Cuda 168 performs well on both salt and fresh water. The Cuda focuses on ease of use, which helps the kayaker juggle fishing rods and a paddle without having to worry about the fish finder, too. Its gray scale screen works well in sunlight. The transducer offers a 60-degree detection area, providing the paddler with a wide overview of the area under his kayak.
Garmin Fishfinder 160C
The 160C is a rugged, waterproof and light fish finder. The display features a crisp color screen that anglers find easy to read in the sun. The supplied cables easily fit under a hatch cover, which means fewer holes to drill into the kayak. The dual-beam transducer provides a wide beam including areas off to the side of the kayak. The dual-beam also provides excellent coverage in shallow areas---no more losing track of the fish when paddling into the shallows.
Hobie Fish Finder Package
Hobie, a fishing kayak manufacturer, offers a fish finder package for kayaks. It includes a Lowrance X50-DS finder, a RAM mount and an installation kit that includes everything needed to mount a fish finder to a kayak. Customers of Austin Canoe and Kayaks, a large kayak-fishing retailer in Texas, rated this kit 4.5 out of 5. In their comments, they say the finder is easy to mount, doesn't require a large battery and works like a charm.
The Humminbird RF35 comes in two parts: a wrist-mounted display and an advanced remote sonar sensor. The angler wears the wrist-mounted display like a wristwatch. This keeps the display out of the way of paddle strokes and allows the user to turn the watch to avoid glare. The sonar sensor floats, so it can be attached to the kayak with a short line and left alone to float. This prevents the kayaker from having to drill holes or mount a transducer in the kayak. The sonar uses a single beam signal narrowed to 20 degrees for a precise focus of the bottom---separating the fish from bottom structure on the display.