One of the drawbacks of forward-looking sonar has always been that sound travels much more slowly through water than radar waves travel through air. At a sluggish 5,000 feet per second, it takes half a second for a sonar “ping” to travel out and back to an object a quarter of a mile away. So for a scanning sonar to build up even a crude picture of what's ahead can easily take several seconds.
But Interphase's latest PC-based forward-looker captures its entire 90-degree field of view with a single ping, using phased-array technology to transmit several beams at once rather than scanning a single beam from side to side.
The result is that at short ranges it can refresh its screen image up to 24 times per second, and even at its maximum 1,200-foot range, the picture is updated twice a second—200 times faster than previous Interphase units. That means you can locate schools of baitfish or fast-moving predator fish in real-time. And when it's time to find your way back into harbor, the Ultrascan can be switched to vertical-scanning mode to reveal underwater hazards.
Early versions of the Ultrascan hardware consist of a through-hull or transom-mounted transducer and a red “black box” processor with an Ethernet connection to a PC or Mac, though it's almost certain that later versions will be compatible with mainstream multifunction displays from manufacturers such as Furuno, Garmin, and Raymarine.
The price hasn't been fixed yet, but it's likely to be about $4,000.
Interphase (831) 477-4944. www.interphase-tech.com.
This article originally appeared in the March 2010 issue of Power & Motoryacht magazine.