Thanks for your response/thoughts, Richard, and for your “vote” on this matter.

I’ve yet to cast my own vote, due to conflicting data and sources.

I also thought we had to be counting a lot of muons, then Robert Hart (of hardhack.or.au), who deliberately seeks muons (using coincidence counters) told me that Geiger Tubes are less efficient in detecting muons. That even though muons have quite a lot of energy and are heavier than an electron, they tend not to ionize efficiently —but that I should be wary of lead shielding, which might result in muons causing cascades beta, positron and gamma radiation.

* An industry respected authority and leader of several radiation interest groups plus another guy who runs a Geiger counter company (they get pissed if I use names) have flatly stated that there’s little or no noise, just ionizing events from external sources –like muons –and that without the NORM, cosmic stuff, and secondaries from shielding, a good Geiger counter might read “zero”.

* However, all G-M tube manufacturers plus two other top guys in the G-M/GC industry have told me that all G-M tubes made since the war have noise.

** Again: my 2 meter depth submerged readings were cut in half –suggesting that the radiation was coming from above (since I was out over the water), that since 2 meters of water stopped half of it, it’s not muons, and that even an SBM-20 G-M tube doesn’t have much noise.

I did that test to verify similar results that a technician for a highly respected private network got (who asked not to be cited).

Again: all this leaves me with a concern for the meaningfulness of our background monitoring, but without an opinion as to the source/s of our *clicks*.

* Possibly: what we see of muons (with a Geiger counter) is just showers of secondary stuff, which does get stopped by a few feet of water.

** Any more votes from this group?