Like most tropical islands, the steady temperature found in the Cook Islands, coupled with the shallow parts of the lagoon make any water activites in Rarotonga more than just pleasant.
The waters are crystal clear within the lagoon and because there are a number of active raui (marine reserves) in place, you have the opportunity of seeing some really diverse forms of marine life when it comes to snorkelling and diving.
Even if you are not a great swimmer and prefer the 'comforts of home', Pacific Resort's glass bottomed boat, for examaple, is on hand offering almost as good a view.
The coral reefs make for excellent exploration points and you can choose between the shallow parts of the lagoon, which the smaller fish use as a nursery, through to the deeper spots where you can either simply enjoy the view, hand feed some of the bigger fish, or if not in a reserve, spear fish.
Other activities include a strong sailing contingent, led by the Rarotonga Sailing Cub. Here you'll find everything from the original P-class babies through to the bigger boats. Again, there's as much fun and opportunity to be had as a spectator as there is to participate.
Kayaking is a second nature to both locals and tourists with almost all resorts, big or small, offering these easy forms of explorative transport around the lagoons.
And if you just feel like a relaxing day out on the briny, you can take advantage of one of the many lagoon cruises on offer, some of which include lunch and time out on an uninhabited motu (islet).
For those who like to spend their aquatic time productively, there are some excellent fishing spots, whether small or game sized. In fact game fishing is comparable to anywhere else in the world outside of New Zealand (known internationally for its consistent entries into world records).From watching the annual migration of the humpback whales and the leisurely movement of the resident Pilot whales, Rarotonga offers something for everyone. And not just the lagoon either.
Tours include some exciting negotiation of rivers or a trip to the beautiful Wigmore Waterfalls. Whatever your taste when it comes to water, Rarotonga offers a truly diverse and enjoyable way to spend your leisure time.