1️⃣ Diamond Core Drilling (HQ/NQ/BQ) Produces intact core — the gold standard. If you want RQD, fractures, UCS, structure, or lab tests, this is your method. → Best for: Tunnels, dams, slopes, deep exploration. 2️⃣ Reverse Circulation (RC) Drilling Fast, efficient, and cost-effective. Delivers rock chips, not core. Brilliant for quick decisions in hard rock. → Best for: Reconnaissance, orebody delineation, grade control. 3️⃣ Down-The-Hole (DTH) Hammer A pneumatic hammer breaks very hard rock with ease. High penetration, low cost, no core. → Best for: Hard volcanics, blasting holes, geotechnical boreholes. 4️⃣ Top Hammer / Percussive Drilling (Jackleg, Stopper, Jumbo) High-frequency drilling where mobility matters most. If you’ve been underground, you’ve heard it before you saw it. → Best for: Underground headings, stopes, tunnel blasting. 5️⃣ Rotary Air Drilling (Tri-cone Bit) Fast and cheap. Produces cuttings only. Love it for dry, competent rock. → Best for: Recon drilling, pre-collar holes, shallow investigations. 6️⃣ Rotary Mud Drilling (in Fractured Rock) When the rock mass is weak, crushed, or sheared — mud keeps the hole open. Not ideal for core, but perfect for stability. → Best for: Shear zones, faulted rock, geotechnical instrument holes. 7️⃣ Horizontal / Directional Core Drilling When you need rock data in a specific direction — especially in tunnels or dams. Game-changer for proactive hazard detection. → Best for: Tunnel face probing, slope anchors, deep foundations. 8️⃣ Sonic Drilling (Moderately Hard Rock) Vibration-assisted advance that preserves core in weathered rock where diamond drilling struggles. → Best for: Rock-soil transitions, altered rock.