Big Blue - Similan Islands

Big Blue, off the Similan Islands, often gets overlooked for some of the flashier sites nearby, but it’s a solid dive, especially if you’re into the smaller stuff. We usually find a good mix of nudibranchs here, tucked into crevices along the reef. It’s mostly a gentle slope, making it a good choice if you're feeling a bit rusty or just want a relaxed dive to focus on your photography. Look for the Indian Scads schooling near the drop-off, and we’ve seen eagle rays cruise by early in the morning. A great place to unwind after a current-heavy drift.

Location
Similan Islands, Thailand, Southeast Asia
Coordinates
8.643159, 98.251495

Marine Protected Area: Khao Lak - Lam Ru

Best Time to Dive in Similan Islands

The warmest water temperatures in Similan Islands occur in May, averaging 30.8°C. The coolest conditions are in January at 28.6°C.

Monthly Water Temperatures

  • January: 28.6°C
  • February: 29.0°C
  • March: 29.6°C
  • April: 30.6°C
  • May: 30.8°C
  • June: 29.9°C
  • July: 29.6°C
  • August: 29.3°C
  • September: 29.0°C
  • October: 29.0°C
  • November: 29.2°C
  • December: 28.7°C

Nearby Dive Sites in Similan Islands

Nearest Dive Centres to Big Blue

Marine Life in Similan Islands

Home to 183 recorded species including 127 reef fish, 38 hard corals, 9 seagrass & algae, 4 sharks & rays, 2 other, 1 octopus & squid.

Notable Species

Recommended Packing List for Big Blue

Based on average water temperature of 29.4°C, currents 7 cm/s.

  • Shorty or Rashguard - warm 29°C water needs minimal exposure protection
  • Mask - essential for every dive
  • Fins
  • BCD - buoyancy compensator
  • Regulator - your most safety-critical piece of gear
  • Dive Computer - tracks depth, time, and NDL
  • Surface Marker Buoy (SMB) - essential for boat pickups
  • Dive Torch - useful for crevices and colour at depth
  • Underwater Camera - capture your diving memories