In water grounding? Ground side control?

[timothyalderson]

Just curious if anyone has tried using a method of grounding thru the water, kind of like underwater welding where you just drop the ground in and run the stinger to the job? And a second question. Anyone using ground side control? Using 1 large power cable then splitting to all thruster and accessories and then running separate small grounds back up the umbilical with the control on the ground?

[Dutch-depts]

unfortunaly that wont be efficient. Water itself has a higher resistance then disired. It would be much more efficient to run an extra wire for ground down to the rov.

As for the multible wires to the surface, those where the first controls for rov's. You must be aware that doing so you must take into calculation that the commen supply wire and the ground return wires are resisitive high.

[timothyalderson]

I knew the Ohms would be relatively high for using the grounding in water. But in short distances (50' or less) it might work? Just curious if any had tried it, fresh and salt water. I'm trying to think of a creative way to make the umbilical smaller somehow. Just throwing ideas out there. I already started piecing my Unit together. Ill post pictures when I can

[Mareike]

The smallest and even cheap solution would be a fiber optic tether. I got one for just about a $ per meter. Also 2 converters were just the at 100$ maker each..
I use a 4 singlemode core in case I break one of the fibers, so I have 2 spare..
I have 10 x 12V/9A Batteries as weight and power supply inside my ROV what gives a lot of stability extra..