I am dealing with an unusual underwater question. I am building some
underwater gold equipment. This will have a large *** on it, that
weighs approximately 30#. It generates 950# impact. It is rated at
approximately 95 db noise when operated on the surface in air. There is a
model available that has slightly less impact, and 20-25% less noise that I
could use, but it is 30% more in cost.
I have dove for a very long time, both scuba and commercially, but I am at a
loss to know what the effect will be underwater. The operator will be
within six feet of the underwater unit while in use, and for the most part
cannot distance himself from it. The use will be intermittent, operated by
a hand valve, meaning on/off, on/off, and sometimes on for a couple of
minutes at a time.
I have used underwater scalers, water blasters, air chisels, jetting
nozzles, and other devices, and can't recall ever being uncomfortable
underwater with the noise levels. But then, I am about as deaf as a lemur
right now, and wear hearing aids, but that has to do with huge overexposure
to industrial noise over the years, and improper safety equipment.
Do you think that this will be uncomfortable for the underwater operator?
Will the noise amplify or deaden? Will the water absorb enough of the
decibels to bring it under the 85db OSHA limits? I do not know if it would
be possible because of equalization issues for a person to even wear the big
ear muff type hearing protectors underwater if the noise were to be too
much. Probably enough water and air could go around the edges to make
equalization not to be an issue.
What do you think? Use the noisy one, or get the quieter one and pay the
money? Or will the noise be an issue at all?