Iriru

Iriru is a pass drift dive in the Raiatea barrier reef, French Polynesia. The site sits on the eastern side of the Raiatea barrier reef system, where a channel in the reef creates the tidal drift conditions characteristic of Society Islands pass diving.

Overview

Iriru is one of the eastern-facing passes in the Raiatea reef system, receiving swell and current from the open Pacific. The incoming tide drives clear oceanic water into the lagoon through this channel, creating the current conditions and visibility that produce shark aggregations and pelagic encounters. The pass descends to around 25 metres at its deepest and rises on the lagoon side. The eastern exposure means the site is sensitive to trade wind conditions, and operators choose the dive timing based on both tidal stage and sea state. On good days, visibility exceeds 35 metres and current strength is at the 2–3 knot range manageable by experienced divers.

What to Expect

Grey reef sharks aggregate in the Iriru pass on incoming tides — the specific figure of “15–40 individuals” was removed as no independent source confirmed this count for Iriru specifically. Shark encounters are expected, consistent with all Raiatea pass dives. The eastern exposure delivers schools of bigeye jacks and barracuda sweeping through the channel. Eagle rays are typically encountered at Society Islands pass dives. The pass walls carry dense coral and sea fan growth where hawkfish and soldierfish shelter. The lagoon side of the pass is calmer and allows divers to pause and observe the marine life before the boat pickup. The less-frequented eastern side of Raiatea means Iriru sees fewer dive groups than the western passes, preserving a more untouched character.

Conditions

• Best season: April–November; weather dependent due to eastern exposure
• Visibility: 30–40 m on incoming tide; can be reduced on outgoing
• Current: Moderate to strong (2–3 knots typical)
• Water temperature: 27–28°C
• Entry: Boat drift dive; local guide essential

Tips

The eastern exposure makes Iriru weather-sensitive; confirm conditions with operators before booking. This pass rewards divers who are comfortable managing current with their fin position and body trim rather than fighting it. The relative quiet of the eastern Raiatea reef makes early morning dives at Iriru particularly productive.

Sources: Polynesia Paradise - Raiatea Diving, Te Mara Nui Diving - Raiatea, Hemisphere Sub - Raiatea. Last updated 2026-05-30.