Retak Larry

Retak Larry is a muck dive site in the Lembeh Strait, North Sulawesi, Indonesia, named after Larry Smith — an American dive pioneer credited with opening the Lembeh Strait to the wider dive world in the mid-1990s and, in 1997, with leading the first documented video of the mimic octopus at this site. “Retak Larry” translates roughly as “Larry’s crack” — the name was coined by his dive staff as a good-humoured reference to a wardrobe incident during a dive, which Smith reportedly accepted with characteristic humour. The site has become one of the best locations in the strait for finding multiple cephalopod species on a single dive.

Overview

Retak Larry runs along a sand and rubble muck slope on the Bitung side of the strait, reaching a maximum depth of 18–20 metres. The substrate is mixed: open black sand where mimic and wonderpus hunt in the open, with rubble patches and den sites for octopus and other critters. Current is described as very light. Visibility averages 8–15 metres. Water temperature holds at 26–29°C. The site also works well after dark, with stargazers buried in the sand and Bobbit worms active after nightfall.

Site Information

• Location: Lembeh Strait, North Sulawesi, Indonesia (Bitung side)
• Entry Type: Boat dive
• Site Type: Muck dive
• Difficulty Level: Intermediate
• Maximum Depth: 20 meters
• Typical Visibility: 8–15 metres (25–50 feet)
• Current: Very light; well-sheltered site
• Best Time: Year-round; daytime for mimic octopus; night dives for nocturnal species

Marine Life

Sources confirm hairy frogfish, coconut octopus, and wonderpus during daytime dives, with seahorses, ornate ghost pipefish, and peacock mantis shrimp also documented. The mimic octopus (Thaumoctopus mimicus) has a documented history at this site since Larry Smith’s 1997 video work here. At night, stargazers buried in the sand and Bobbit worms emerge from their burrows. Blue-ringed octopus are present in the rubble zones and must be treated with extreme caution. No additional site-specific species lists were found beyond what sources confirmed above — the description does not attribute species to this site from regional lists.

Dive Profile

Work the slope between 5 and 18 metres, dividing time between the open sand areas where wonderpus and mimic octopus hunt, and the rubble zones where other octopus and frogfish shelter. The guide will know the active den locations for resident octopus — follow their movement direction on the slope. The site’s shallow maximum depth allows extended bottom times, which is useful for patient observation of octopus hunting sequences. Night dives are operated from the site’s protected, sheltered position.

Entry and Exit

Access by banca boat. Back roll or giant stride entry. Follow your guide closely. Surface with SMB deployed.

Tips and Recommendations

• The mimic octopus is diurnal and most active on daytime dives — for this reason Retak Larry is an excellent daytime rather than night dive choice for the headline species
• When a mimic octopus or wonderpus is found hunting in the open, resist the urge to approach closely — moving too fast triggers retreat to a burrow; hover at 1–2 metres and observe
• Wonderpus versus mimic identification: wonderpus has a distinct spotted pattern with white-outlined brown patches and longer arms; mimic is more uniform brown with white stripes; ask your guide to confirm which species you’re looking at
• Blue-ringed octopus are genuinely dangerous — never handle any octopus at this site regardless of size; the blue rings brighten only when the animal is agitated
• For night dives, a primary torch and backup are essential; also bring patience for Bobbit worm encounters, as the worms may take time to emerge

Safety Considerations

Blue-ringed octopus are a genuine hazard at Retak Larry. Their venom causes paralysis and can be fatal — no antivenom exists. They are small (3–6 cm body) and cryptic. Never touch, pick up, or place hands near any octopus at this site. Stargazers buried in the sand can deliver electric shocks — do not kneel directly on the sandy bottom. Standard Lembeh buoyancy and silt precautions apply. Carry an SMB.

Photography

Retak Larry is a behaviour photographer’s site. Mimic octopus impersonating flatfish — spreading arms symmetrically and undulating across the sand — is one of the most sought-after sequences in muck diving photography, with a documented history going back to Larry Smith’s original 1997 footage. Video is strongly recommended for capturing the full behaviour. For stills, a 60mm lens provides enough working distance to frame the animal in hunting posture without disturbing it. Wonderpus patterns are best captured under supplemental strobe light. Blue-ringed octopus showing threat-display blue rings should only be photographed from distance; never provoke the display.

Sources: Infinite Blue Dive Travel – 15 Best Lembeh Sites, Wetpixel – Larry Smith, ZuBlu – Lembeh Strait, Lembeh Resort – The Man Behind the Mimic Octopus, Starfish – Lembeh Dive Sites. Last updated 2026-06-14.