If one has a surveyed depth and radio located point on surface, but has to dig a horizontally inclined tunnel to the point underground, how does one stay on track to the point. Ie; xM distance and xM depth?
One could go over/under or to the sides of the surveyed point.
Is it just a question of using compass and declination or are there sophisticated items on the market, ie; Laser beams/theodolites etc?
Any help or pointers would be greatly appreciated. Have tried creg but no lick so far?

If you know the depth and distance, you can calculate the angle you need to tunnel at. So could you  not use a laser pointer of some type set pointing accurately at the correct angle and direction and every now and again switch it on to confirm you haven't strayed off line. You could use a scaffold pole or smaller diameter pipe to get the correct angle and mount the laser on the top end shining down the tube.

Maj.

Thanks Maj,

I don't see why not?
Sounds logical to me, unless someone knows different....?