Selected Hydrophone Field Recordings
Headphones Recommended

San Gabriel River outlet
Croakers were doing their thing, croaking. It took me a little bit of research to discover just what was making these noises but many types of Croaker are common in Seal Beach where this was recorded.
Recorded with the DIY Hydrophones and Tascam DR40x

Hydrophone Experiments
I was getting some auto noise while the hydrophones were in the water so I figured I might as well try to strap them to the bridge railing and see what happened. Kind of a spacey mono-rail type sound.