After intense R&D investment, underwater acoustics specialist RTSYS has released the long-lasting and cost-effective SYLENCE-LP acoustic recorders. Two recorders were developed: a smaller one named SYLENCE-LP 220 (22 cm high, 35 days of autonomy), with one fixed hydrophone; and a longer one named SYLENCE-LP 440 (44 cm high, up to 180 days of nonstop recording), with one fixed or loose hydrophone. These recorders