Furuno's new SC-30 can sense a boat's sea motion (pitch, roll, and heave) and relationship to Earth—i.e. position, heading, COG, SOG, and ROT (rate of turn). And it feels all that with astonishing accuracy and speed, as I witnessed at least in part (see "Time Zero, Live"). Unfortunately, we didn't have seas big enough to directly test Furuno's claim that its fishfinders can use SC-30 heave info to correct wavering bottom and fish echoes. But we saw that just two feet of vertical motion applied by hand to an unattached SC-30 registered instantly on a DFF1 (NavNet 3D's digital fishfinder) screen, which shattered my prior skepticism about this feature. And thus, though also personally untested, I now believe the SC-30's pitch-and-roll data is good enough to correct sonar beam motion, as illustrated. The "less than $3,000," 27-inch-long SC-30 contains two WASS GPS receivers, a three-axis rate gyro, acceleration sensors, and a processor running an algorithm developed at a Dutch university (another sign of Furuno's global development style). The standard unit uses NMEA 2000 for power and data, but an optional interface box can translate its output into several other protocols.
This article originally appeared in the August 2008 issue of Power & Motoryacht magazine.