Aqua Locator

© Brooke Clarke, N6GCE

Aqua Locator Front w/o carry case
Aqua Locator Top w/o carry case


Reading water meters is made more difficult in that some are not read frequently and so they get hidden by weeds, dirt blown by the wind, etc.  In order to make finding them easier a number of products were developed, the Aqua Locator is one of them.  This product is not a "water witching" device but rather a magnetic dip needle that's optimized for locating ferrous metal in the ground, like a water meter, but can be used for finding any ferrous metal that's relatively near the surface.  It's a compass that works on the up-down part of the field (which is stronger than the horizontal field in most of North America).


I don't have a manual for this instrument, if you do please contact me.

When the instrument is turned face up it acts like a conventional azimuth compass, except the window only displays the cardinal directions NW - N - NE, but by turning the case you can get the Red end of the needle to point North.  Then the Aqua Locator is held a few inches off the ground using the carry strap and is oriented with the North arrow on the case pointing North.

Now maintaining the North direction slowly move the locator over the area where ferrous metal might be located and look down at the image of the needle in the 45 degree mirror.  When over ferrous metal the needle will move to a vertical position.

When I brought the locator over a metal stake that was driven into the ground with a sledge hammer the needle flipped over, i.e. instead of seeing the Red end the Black end was pointing up!  The stake probably was made into a magnet when pounded into the ground.


Sam Poon was kind enough to send the instructions and here they are (less an image of the locator):
for use of the
The following is a series of steps in the use of the Aqua Magnetic Locator. Please follow them carefully for 100% satisfaction:
1. Open flap on leather case. (Instrument need not be removed from case.) Turn AQUA
    on its side, bottom of case toward you, NW, N, NE dial level. In this position, your
    AQUA is a compass. Point dial portion north until red end of needle points exactly at
   "N". You now have true north position.
2. Turn AQUA upright, point gold arrow on leather case to "N", as was indicated
    by instrument in step #1. (When leather case is very new, it is helpful to fold
    the flap down firmly so that it will remain in position when in use, and not
    obscure the dial.) Using carrying strap, lower instrument to just a few inches
    above ground, holding instrument carrying strap over four fingers. Holding strap
    by four fingers minimizes chances of instrument twisting out of position as
    you walk. Be sure that "N" is still pointing north.
3. Begin "walking" the instrument in parallel paths, about 12 to 15 inches apart,
     until the red end of the needle dips and the black end of the needle appears.
    Find the point of maximum reading: that point at which black end comes nearest
    to "90" mark. At this point, walk at right angle to former path, still keeping
    instrument pointing toward north, until maximum reading is found on right angle
    path. This is the location of missing valve box or stake.
When object to be located is very deep in the ground, or heavily covered, a full deflection
to "90" mark cannot be expected. In cases of this kind, "70" or "75" may be the best reading obtainable.
In areas where there are high voltage overhead wires, there is usually electrical disturbance, which will cause the red end of the needle to show on dial. This does not hamper location operations. When over the object, red end will disappear and black end will appear on dial.
Where shrubbery or other obstructions prevent the strap method of holding instrument, AQUA may be removed from its leather case and metal rim pulled up and used as a
handle. However, whenever possible, keep AQUA in leather case, as a protection
against possible damage from bumps and jolts.


Dec. 25, 1956, Christmas day the patent office must have been working, US patent number 2775736 was granted with the assignee Aqua Survey & Instrument company, Cincinnati, Ohio. the patent classes are: 324/260; 33/345; 33/348; 116/303; 324/67; 324/156; 324/228; 324/326


These show up on eBay from time to time.
Back to Brooke's PRC68, Products for Sale, Sensors, Military Information, Personal Home page

This is the  page created 5 July 2003.