In Through The Out Door – Mergui Archipelago – Southern Sites Dive Site

12m Max

15-35m Vis

boat

Site Overview

In Through The Out Door is one of Mergui Archipelago – Southern Sites's most rewarding dive sites, offering a shallow coral garden sloping through a natural arch formation with reef octopus, blue-spotted rays, and abundant macro life. The site's healthy marine ecosystem supports diverse fish populations and vibrant coral formations throughout the diving season, creating an underwater landscape that rewards repeated exploration. With consistent water temperatures of 27 to 30 degrees Celsius and visibility regularly exceeding 15 meters, In Through The Out Door provides excellent conditions for underwater exploration and photography across all certification levels. The site's diverse topography creates multiple habitat zones supporting different species at various depths, from shallow coral gardens teeming with juvenile fish to deeper sections where larger pelagic species patrol the blue water. Nutrient-rich currents flowing over the reef structure sustain abundant filter-feeding invertebrates including gorgonian sea fans, sponges, and crinoids that add spectacular color to the underwater scenery. The remote pristine location of the Mergui Archipelago ensures excellent coral health with thriving hard and soft coral communities providing critical habitat for the diverse marine life. Seasonal variations bring different species into the area with the dry season months consistently delivering the best combination of visibility, calm conditions, and active marine life encounters. Whether diving the shallower sections for macro photography or exploring the deeper walls and pinnacles for wide-angle opportunities, In Through The Out Door delivers memorable underwater experiences throughout the diving season.

Dive Briefing

"Begin the dive at the shallowest point of In Through The Out Door and take a moment to orient yourself before descending along the natural arch coral garden. Maintain excellent buoyancy throughout the dive to protect the fragile coral formations and diverse marine life inhabiting the reef structure. Swim along the formation exploring the various depth zones while observing the diverse habitats and marine species that occupy each zone. Check overhangs, ledges, and crevices for resting turtles, moray eels, and cryptic critters that shelter from the current. Pay special attention to the coral bommies and gorgonian fans where smaller species like pygmy seahorses and nudibranchs can be found with careful observation. Monitor your depth and remaining NDL carefully throughout the dive and maintain conservative ascent profiles, especially when moving between different depth zones. Keep your dive buddy in visual contact and communicate regularly using standard hand signals. Complete your safety stop at 5 meters deploying your DSMB before surfacing near the boat, watching for boat traffic overhead during your ascent."