The Raro Reef Sub offers a unique semi-submersible adventure in the Cook Islands. Departing from Avatiu Harbour in Rarotonga, this tour allows visitors to marvel at the stunning island views from the observation deck or descend into an underwater wonderland to explore the vibrant marine life and discover a century-old shipwreck. The tours, lasting between 1 and 1/2 hours, are suitable for all ages and take place from Sunday to Friday, offering multiple departure times throughout the day.

As the vessel is not a submarine, but a sturdy steel boat with slanting windows, visitors can choose to sit on deck or climb down a vertical ladder into the hull to view underwater. People with mobility issues may find descending the ladder challenging. While there are around 14 windows, only four have seats, so arriving early is recommended for a comfortable viewing experience. Crowded conditions may lead to a rotational system where visitors take turns downstairs, with the opportunity to experience the island scenery from the deck as the vessel returns to the harbor.

During the tour, guests can observe various marine creatures such as giant trevally, tropical fish, stingrays, turtles, eels, and even humpback whales during the whale season. While the coral may appear mostly dead or broken due to cyclones and crown of thorn starfish attacks, visitors can witness the remains of a shipwreck and coral-encrusted artifacts on the seabed, offering a unique insight into underwater history.

The Raro Reef Sub offers a safe and enjoyable experience for families, with ample handrails and sufficient seating. Additionally, charter options are available for groups of up to 16 people. It is advisable to book in advance, especially during peak tourist season, to secure a spot on the tour. Overall, the Raro Reef Sub provides a worthwhile experience, particularly for children, offering an informative and captivating look at the underwater world just beyond the enchanting Cook Islands reef.