I'd only been snorkelling in Rarotonga's Muri Beach lagoon for a few minutes when something whacked my foot with so much force it felt like an electric shock.
I quickly looked up to see four or five large bluefin trevally racing off into the distance, on the hunt for their lunch perhaps, or maybe just playing around in the water like I was.
In his haste one of the hefty creatures - so big thanks to the fact we were in the Tikioki Marine Reserve where fishing is banned - had banged into my foot, leaving a harmless cut between two of my toes.
We'd motored out from pretty Muri Beach that morning on the Koka Lagoon Cruises glass-bottom boat, as, after a prayer, the talented and funny crew - Captain Awesome (Papa Jack), Captain Cook (Papa Toru), Captain Amazing (Tairi), Captain Jack Black Sparrow (Nga) and beautiful Vaka Mermaid Terito - serenaded us with a few songs, accompanied by ukuleles and drums.
There was a bit of drizzle and low cloud about but the day was still warm and it came as a relief to do a big bomb into the slightly cool lagoon and beetle about in its pristine water as the colourful reef fish and the bullish trevally darted about around - and into - us. The crew advised us to steer well-clear of the vicious fire coral, which delivers a painful sting, and happily there was no sign of Roger, the 2.5m-long moray eel - that's one fishy encounter I was pleased to avoid.
After about an hour, the deep bellow of a conch shell let us know it was time to get back into the boat and head for Motu Koromiri, one of four uninhabited postcard-perfect islands within the reef, for a barbecue lunch. On the way the crew kept us entertained, with lessons in pareo (sarong) tying and more singing.
That sea air makes you ravenous. After a big feed of fresh yellowfin tuna, sausages, fruit, pawpaw salad and more, Captain Amazing handed us over to Awesome, one of the fastest coconut-tree climbers in the Pacific and a star of Air New Zealand's Sports Illustrated safety video.
Awesome - a consummate showman whom we spotted dancing later in the trip at the Te Vara Nui Village cultural show - emerged in traditional dress and taught us Coconuts 101.
He roped in a few of the "warriors" (males) in our group to have a go at scaling the smooth trunk of the coconut tree, made all the more difficult thanks to the recent weather. After three of them failed miserably to even get a foothold, Awesome took over, romping to the top in a matter of seconds, knocking down half a dozen coconuts, then sliding down again, quick as a flash.
A full run-down of the many uses of this versatile drupe (botanically not a fruit or a nut) followed, before we finished our tour with a bit of hermit crab-racing down on the beach.
This time it was my finger that had the encounter with the local sealife, as Barry, my grumpy crab, gave it a good nip on his way to the start line.
Air New Zealand flies non-stop to Rarotonga from Auckland six times a week. One-way Economy fares start at $299. airnewzealand.co.nz
Koka Lagoon Cruises leave daily from Muri Beach. Prices start at $79pp for adults, $40pp for children 5-11, under 5s free.