This is not a beach destination with an excursion attached. It is a destination of one plan, repeated, with Nuku'alofa as the place to sleep, eat and wait for tomorrow.
01 A season with a date in the rulebook
The legal window for swimming runs from 1 July to 30 October. Around Tongatapu the whales show a little earlier and a little later, from mid-June to the end of October, but outside those dates you may watch and you may not get in.
The rules are strict and worth knowing before you book. Only accredited operators may approach within three hundred metres, and only those additionally licensed for swimming may put people in the water. Once in, you keep at least five metres from the animal, you stay as a group with the guide at all times, and scuba, artificial lights and noise are not allowed.
A maximum of four swimmers go in at once, plus the guide. Boats usually carry eight clients and alternate two groups of four, so half your time is spent watching from the deck. August and September are the best months.
02 What a day on the boat is like
A full trip can run to seven hours. You leave early, motor around looking for blows and tails, and much of the day consists of watching the horizon with nothing happening. When an animal appears, the boat closes in slowly and the guide decides whether the encounter is suitable to enter: not all are.
The best are resting mothers with a calf, which stay still near the surface while the calf comes up to breathe every few minutes. There the encounter can last a good while. Other times the animal moves off and the whole thing is over in a minute.
And there are days when you do not get in. No operator guarantees the encounter, because nobody can. That is the underlying reason to book five or six nights instead of two: not to see more, but to have more attempts.
03 The days the sea will not allow
When the wind cancels the trip, the island can be driven end to end in a day. In the east stands the Haʻamonga ʻa Maui, a trilithon of coral limestone blocks raised centuries ago, with one block slotted horizontally across two uprights.
Nearby, at Lapaha, is the group of langi: more than twenty ancient burial mounds, stepped stone platforms that have stood in the same place for centuries. And on the south coast, the cliffs: the Hufangalupe arch and the rock line where the sea leaps in plumes of spray.
For water without whales there are the islets opposite, half an hour by boat from the capital, with shallow reef and sand. It is the obvious fallback and works well for half a day.
04 The practical part
Book the operator months ahead if you are going in August or September: licensed places are limited by design. Carry cash, because outside the capital a card does not get you far, and bear in mind the international airport is 34 to 37 kilometres away, in the south of the island.
In the luggage, a thin two or three millimetre wetsuit: in August and September the sea drops to 23.5 degrees, and seven hours out of the water, wet and in the wind, chill you more than you would think. Add a long-sleeved layer for the nights, which in July sit at 18 degrees.
A calendar note that saves disappointment: Sunday is a general day of rest across the country and almost all shops, restaurants and boat trips do not operate. Factor it into your attempts and do not discover it on Saturday night.
05 How to build five days
Day one, arrival and settling in: pick up the car or arrange transfers, change money, confirm the operator in person and walk the waterfront. Early night.
Days two and three, sea: two full trips back to back. This is the heart of the trip and they are best placed early, leaving spare days behind them if the weather turns or the encounter does not come.
Day four, land: the island circuit, with the trilithon and the mounds in the morning and the southern cliffs late in the afternoon, when the light on the rock is at its best.
Day five, wildcard: if the sea days went well, islets and snorkelling; if not, a third trip. And if you have one more night, do not look for anything new: go back to the boat.
Michael Coghlan Funafuti, for the traveller who spends the evening on a runway.
Earth Science and Remote Sensing Unit, NASA Johnson Space Center Honiara, for the traveller who comes to see a volcano that incubates eggs.
Gelu Purcelu