I have worked on some similar problems with ROV's, from my experience you might want to look at an underwater acoustic system try SSBL (super short baseline) or USBL (ultra short baseline). The systems are definately robust and designed to be imersed. They are also relatively expesive
Try...
This depends on the accuracy and sounding density requirements, the width, depth and current velocity of the water body. I have done a fair bit of river hydro-work with both single beam systems and sounding rods / chains. This sounds like a sounding chain problem. I would be more than willing...
I am wondering if anyone is aware, or knows a source for "Cat Equipment" AutoCAD or Microstation block drawings.
Essentially I am looking for block drawings of track mounted excavators from 325 to 5130 size, haultrucks up to 777 size as well as wheel loaders from IT28's to 988's.
Thanks