Simrad announced in October the first recreational sonar to incorporate CHIRP technology, another name for frequency-sweeping pulse compression. CHIRP produces higher resolution - Simrad says up to five times higher - at deeper depths with less noise. In testing, the company marked depths to 10,000 feet. The 3 kw BSM2 also uses enhanced digital signal processing, and paired with Airmar's broadband transducer lineup, provides clearer images of individual fish and better separates fish from structure, thermoclines and the bottom, Simrad says. The unit's low-frequency transceiver operates at 25 to 45 kHz; the high-frequency transceiver supports 40 to 60 kHz and 130 to 210 kHz. Available in March, the module will cost $2,495 without a transducer. Call 8006284487, or visit www.simrad-yachting.com.