Eufaula, Ala. ? With its bright green outer casing, some people might guess it was a crudely fashioned plastic Easter egg. Others might see its oblong submarine design and mistake it for a child’s swimming pool toy.

But never in a million years would an uninformed person peg the Humminbird RF 10 for what it really is — a depthfinder.

The innovative new unit weighs roughly an ounce, fits easily in the palm of your hand and resembles the simple plastic floats used by bank fishermen everywhere.

However, inside its waterproof plastic casing is a small computer brain similar to the ones found in the transducers that have long accompanied traditional depth-sounding products.

Tied to the end of a fishing line, the unit can be cast into the water where it floats on the surface and beams perfect depth and bottom readings back to a portable, high-resolution screen via wireless remote.

It’s a product that will give many fishermen views they’ve only imagined before now.

“When I was fishing farm ponds as a kid I would have given anything to have something like this to give me an idea of what was out there under the surface,” said Mark Gibson, global product manager for Techsonic Industries. “That’s what we’re trying to do. We’re offering that kind of fisherman a whole new product and opening a whole new world.”

The RF 10 — a product from Humminbird’s new line of Smartcast wireless fishfinders — is a bank fisherman’s dream. In lakes that can’t be accessed by boat, the unit gives concrete answers to the questions “How deep is this place?” and “What’s on the bottom?”

The RF 10 can be used exclusively as a depthfinding device or above bait as a fishing float. When used as a float, the unit serves as a “spy in the sky,” giving fishermen a heads-up when fish are closing in on their bait.

“That’s one of the things we think a lot of people will like,” Gibson said. “Just imagine sitting on the bank, looking at the screen and knowing that a fish is swimming around your bait. You can see it on the screen and you can hear the fish alarm.”

Gibson said the RF 10is popularity among bank fishermen came as no surprise to the folks at Techsonic. But the units have drawn unexpected interest in several other circles, including tournament bass anglers and saltwater fishermen.

“I think a lot of bass fishermen like the idea of using the RF 10 because they can put it in places where their boats can’t go,” Gibson said. “They can also check brush piles without having to run over them.

“The saltwater fishermen like the units, too — but only in calm water. If you get into rough water, obviously, they’re not quite as accurate.”

In addition to the Smartcast units, Humminbird has introduced a new line of technologically advanced fishfinders known as the Matrix Series.

Matrix units feature large, high-definition LCD displays with ultra-fine detail. One unit from the series — the Matrix 45 — has a full-color display and shows fish in red.