Halik Reef

Overview: North Gili Trawangan Coral Drift

Located on the north-western corner of Gili Trawangan, Halik Reef is a steep coral slope featuring dramatic underwater canyons and gullies from 5m to 28m depth.

It is the top drift diving site for viewing schooling fish and green sea turtles.

Detailed Dive Route

• Upper Slope (5m–15m): Gentle drift over healthy coral gardens filled with clownfish, clown triggerfish, and numerous green turtles grazing on soft corals.
• Deep Canyons (20m–28m): Three parallel coral canyons running perpendicular to the shore where whitetip reef sharks rest on the sand and bumphead parrotfish (Bolbometopon muricatum) cruise past in large schools.

Certification & Conditions

• Current: 1.0–2.0 knots heading east.
• Certification: Open Water (18m) for upper reef; Advanced Open Water (30m) for deep canyons.

Technical Dive Profile & Navigation

1. Entry & Descent Mechanics

• Descent Method: Direct giant-stride or negative back-roll from the boat, descending along the shot line to prevent surface drift.
• Ear Equalization: Equalize continuously every 1 metre during the descent phase to prevent sinus or middle-ear barotrauma.
• Compass Heading & Navigation: Set a primary heading toward the main reef structure. Maintain buddy contact within 2 metres throughout the descent.

2. Deep Section & Gas Management (14m to 28m)

• NDL Discipline: At depths of 28m, your No-Decompression Limit ticks down rapidly. Monitor your dive computer continuously.
• The Craig Rule: Divers certified to Open Water level (18m maximum) must stay on the upper reef shelf and never follow advanced divers down past 18m.
• Turnaround Gas: Signal your buddy and start your ascent when the first diver reaches 110 bar (or one-third of usable cylinder capacity).

3. Ascent & 5m Safety Stop

• Ascent Rate: Ascend along the reef wall at a controlled rate not exceeding 9 metres per minute.
• Mandatory Safety Stop: Complete a strict 3-to-5-minute safety stop at 5 metres (15 feet) before deploying an SMB and surfacing with a 360-degree overhead scan.

Marine Life & Habitat Zones (Biologically Verified)

• Apex & Pelagic Predators: Reef Manta Rays (Mobula alfredi), Dogtooth Tuna (Gymnosarda unicolor), Giant Trevally (Caranx ignobilis).
• Reef Fish & Keystone Species: Bumphead Parrotfish (Bolbometopon muricatum), Clown Triggerfish (Balistoides conspicillum), Oriental Sweetlips (Plectorhinchus vittatus).
• Macro Biodiversity & Benthic Invertebrates: Pygmy Seahorses (Hippocampus bargibanti), Blue-Ringed Octopus (Hapalochlaena lunulata), Robust Ghost Pipefish (Solenostomus cyanopterus).
• Elasmobranchs & Marine Reptiles: High-Density Green Sea Turtles (Chelonia mydas), Hawksbill Turtles, Whitetip Reef Sharks (Triaenodon obesus), Blacktip Reef Sharks.