I thought I'd asked before but a search for PDS-2 finds nothing so it's worth a try.
It's old. It was on Ebay a couple of years ago.
Scubapro UK didn't come up with anything.
Personal Dive Sonar -2
Anybody know anything about it?
I've fixed it enough to turn on and display so I've lubed the O-rings and I'll take it down the pool tonight.
If somebody said "I had one in 1066. I might have a manual somewhere..." that would be nice.