Recorders	Microphones/Transducers	Bat detectors	Shock-mounts
	CompactFlash	Overview	Playback	Cables
	Hard-drive	Shotgun	Headphones	Protective cases
	R-DAT	Parabolic reflector	Speakers	Additional
	MiniDisc	Omni-directional	Amplifiers	Helpful Reads
	Analog	Uni-directional	Accessories	Vendors
		Infrasonic	Preamps	Inquiries
		Hydrophones

For underwater recording, the DolphinEAR/Pro ($299) is a high quality, low cost solution. The omnidirectional device features a 10-meter cable (other cable lengths are optional), 600ohm balanced output that terminates with a standard 3-pin XLR style connector, and a frequency response of 15Hz-20kHz ± 3dB. The transducer is a high-output MPC (Piezo) style, fully encapsulated in a rugged epoxy case. No power is required.

DPA Microphones produces and manufactures an excellent hydrophone. Type 8011, Hydrophone, is a 48-volt phantom-powered, waterproof microphone.  It is specially designed for high sound pressure and high static ambient pressure.