"I don't care what anyone says, there are no sharks in the lagoon," says Tara, our guide on today's cruise. We tentatively put a flipper in the water and prepare to jump. "Watch out!" We clamber backwards. "There are giant clams over here by the boat."
The innocuous molluscs in this Rarotongan lagoon are an assortment of colours, some emerald-green with big, Egyptian eyes on their sides, others browny yellow, all of them huge. Camped out on the hard coral that dapples these otherwise pure turquoise waters with navy blue, they are nature's underwater ornaments.
I'm about to head back to the boat after a leisurely half-hour exploring the lagoon's shallow waters when out of nowhere, a stream of black liquid flies over my head. Tara is blocking my path to the boat with what looks like a giant sneeze strapped to his chest. It's an octopus, and Tara is determined to show off his new pet's party tricks.
Squirting black ink in a panic-inducing trajectory is one of them. Swimming under the glass-bottomed boat with the sneeze still attached so we can take photos is another. It takes him a good 10 minutes to prise the suctioning creature off his torso but it's all in a day's work as guide of Captain Tama's Lagoon Cruizes, a 4-hour trip through Rarotonga's Muri Lagoon on the southeastern coast.
Not to be confused with the founder, Captain Tama, Tara is an athletic local whose brand of humour belongs somewhere between tourist group comedian and lady-loving larrikin. He's particularly keen that all the women touch the well-endowed fertility god carving before we go.
"Put your hand up if you're a Kiwi," he says, as the packed boat sets off from Muri Beach, and several hands go up. "Now get off."
Captain Tama's has been operating for 18 years, offering a chance to escape the civilisation of the resorts for the more beautiful, less developed side to Rarotonga, in this case, a marine reserve dotted with four small islets or motu.
Many Cook Islanders believe that the great Maori migration to New Zealand started not far from here, where there is a gap in the fringing reef at the widest part of the island's lagoon.
You can't help but feel the significance of the place as the boat makes its way to the stunning white sand of Moto Koromiri.
Nor can you complain when Tara and the boat's skipper cook lunch, allowing us to take a dip in the still waters, explore the island or simply laze back under one of the Uto or young coconut palm trees. Most of them were planted by newlyweds, part of a Cook Island custom to symbolise the beginning of new life. Cue a quip from Tara about the dying "divorce trees".
Like the Maori, Rarotongans cook in earth umu ovens but to speed things up today we're served fresh tuna with seared banana, sizzled on a smoky barbecue. "That's why they call us Cook Islanders," hoots Tara. It's not an obvious combination to Kiwi tastes but the dense meat of the fish is lightened by the sweetness of the fruit.
Despite signs on the island proclaiming it a black pearl farm, the pearls in Rarotonga come from Manihiki Island, 1160km north of Rarotonga. What Rarotonga is famous for, however, is its coconuts. The humble fruit are used not just for culinary purposes but to ward off mozzies, as building materials, medicines, bathroom products and as a hangover cure, Tara explains, during an entertaining husking show after lunch. The worst job for any youngster in Rarotonga is grating coconut to extract the cream. "I had to do it for four hours every bloody Sunday," says Tara.
Although there's little audience participation - perhaps out of fear we might pierce ourselves on the sharp point on which the coconuts are husked - our bare arms are treated to a slathering of coconut milk.
There's more bare skin to be exposed yet, as Tara moves on to the art of tying a sarong or pareo. Sarongs can be tied 375 ways, he says, before giving a demonstration on a few willing - and unwilling - models. This includes a ritual of humiliation that involves placing a rock in a man's pareo so it swings between his legs "as a sign of virility". It's all pretty embarrassing but funny - and it's hard to wipe our smiles as we return to shore, Tara strumming a tune on the guitar.
Those keen to get a taste of Rarotonga's marine life but in a shorter time frame should check out the Raro Reef Sub, the only one of its kind in Rarotonga. The boat is only partly submerged, providing views above and below the water.
The Reef Sub departs Avatiu three times daily and cruises along Rarotonga's's northern coast, giving passengers a glimpse at the SS Matai shipwreck without the need for a dive ticket. Unfortunately it's a bit rough today but from the safety of the sub we can make out the Matai's barnacle-encrusted engine and the thousands of colourful tropical fish that have made a home there since the ship came to grief in 1916.
The coral reef is almost close enough to touch.
But with the constant rolling of the boat and no horizon to anchor me, seasickness sets in and I have to return to the main deck. Next time I'll wait for a calm day.
Pacific Blue flies three times per week from Auckland to the Cook
Islands, starting at $344 one way. See www.flypacificblue.co.nz.
Air New Zealand flies nine times per week from Auckland from $289 one
way. See www.airnewzealand.co.nz.
WHAT TO DO
Captain Tama's Lagoon Cruizes departs daily from Muri Beach at 11am Monday to Saturday. Bookings from www.captaintamas.com or phone
682 27350. $70 per person; (half price for children under 12).
The Raro Reef Sub departs three times daily from Avatiu Harbour.
Email firstname.lastname@example.org or phone 682 55901 or 682 55903.
$65 per person; children 15 and under, $35, under 2 free.
Rebecca Barry flew to Rarotonga on Pacific Blue and stayed at the Rarotongan Beach Resort & Spa.