The Final Preamplifier for the acousic disdrometer has been designed and built and is working well.  Below are a few pictures.  The only thing that I would do differently next time is make the whole thing single supply rather than dual supply.  Becuase I have used a rail splitter and connected the ground from that to the ground on the outputs, when connecting to an oscilloscope, the non-earth potential shorts against the oscilloscopes ground which is connected directly to earth.  Short answer is the power pack -> oscilloscope is creating a big circuit so when trying to force the ground to some other potential (mid-rail for example)  it’s never going to win!

PCB, Built PCB, Preamp Cased with Hydrophones