OVNO Hydrophone 
How about the sound under water?
It's a nice microphone to put under liquids and experiment with the sound.
We built with a sensible condenser microphone , it's perfect to use in water or humidity situations.
We currently don't have any experience with recording whales or underwater animals.
 
NOTE: The Hydrophone needs Plug in power between 3-4V, you can connect to almost Portable recorder like Zoom, Tascam, sony, fostex, or we can built a preamp for it. 
NOT WORKS with 48V phantom 
 
ESPECIFICATIONS:
Usable Frequency Range    
20 Hz to 20 kHz
Resonance Frequency    
46 kHz
Receive Sensitivity    
-50 dB re 1V/µPa
Horizontal Directivity    
Omni ± 1 dB to 40 kHz
Vertical Directivity    
Omni ± 1 dB to 20 kHz / Omni ± 3 dB to 40 kHz
Max Operating Depth    
Tested to 20 m
Operating Temperature Range    
-2 deg C to +55 deg C
Storage Temperature Range    
-40 deg C to +125 deg C
Supply Voltage    
3-4 Volts DC
Current Draw    
10 mA

Mechanical Dimensions    
5cm x 1,8cm Length
EM Cable Length    
5 m (Possible with more cable)
Connection: Minijack 3,5 (is possible with Jack 6,3)