SHARE A DIVE

Tonga: Ha'apai Group "The Cathedral"

Location: Just off the NW tip of Maunga'one Island in the Ha'apai Group of The Kingdom of Tonga. Maunga'one lies about 15 nautical miles NNW of Lifuka.

Grade: Advanced. Cave divers certification needed.

How to get there: With Watersports Ha'apai by boat from the Ha'apai Group's main island Lifuka. The weather needs to be good with not too much wind, otherwise you will have problems trying to get back to the main island.

The boat ride to Maunga'one is usually quite easy. You are travelling with the tradewind and the waves. Once in the lee side of Maunga'one, near the dive site, the anchor is dropped.
Maunga'one is a raised coral reef. The western coast of the island consists of hard limestone rock which comes straight out of the sea up to between 10 and 15 metres height. It looks similar to limestone islands in Tonga's Vava'u group and Palau in Micronesia. Maunga'one, though, is a tiny small island not even a kilometre in diameter.
Limestone rocks decay under the combined influence of wave action and rainwater. Often this decay happens in an uneven way, and this is what creates the caves and tunnels found. Almost immediately after descending you can pass under a huge rock outcrop in a low but wide tunnel with sandy bottom.

The visibility here is about 50 m

Get your buoyancy right before entering and be careful not to stir up the bottom. The sand and silt on the bottom will mess up your shots and the divers following you will have poor visibility.

You come out from the tunnel into an open area with an enormous arch across at one end. Not far from the arch the dive master from Watersports Ha'apai will show you a narrow hole. This is the entry to The Cathedral.

Do not attempt diving the cathedral without a local guide, and definitely do not make this your first cave dive.
As you know, cave diving require special training and should not be attempted without the proper certification.
You will need to descend to 28 metres before the cave opens up into a huge vault, with its ceiling at about 10 metres depth. However, there is only one way out, and that is the way you came in.
The cave is absolutely dark, only lit by the light you bring down. Lights on your video housing are essential for this dive. For safety, also bring with you an underwater torch.
Once you are there, settle in and while carefully watching your gauges and no-deco time get some shots of the sharks living in the cave and the lobsters as well.
We made one mistake when doing this dive. The mistake was to spend too much time and air on the approaches to the cave. This left us with only a short time inside the cave itself, given the fact that we had to plan for a safe exit, commencing at 28 metres.
If we were to do the same dive again, we would enter this cave first, and then, once we had the shots we needed, we would exit and get other shots. You learn as long as you live - one problem was that we were not aware of the exact profile of the dive before we started, and the guide was not expecting us to be so slow in getting to the cave itself.

This dive is quite amazing and exiting and you will be able to get some really unique shots. If you have time available for more dives you will also be able to concentrate one dive solely on the Cathedral, and other dives on the surrounding tunnels, the arch and other features.

Maunga'one Island itself is small and with only one tiny village. There is no harbour and you have to negotiate the incoming swell through a narrow passage to get to the beach where landing is possible. Don't count on landing on this island, we have been there twice and only just managed to get ashore on the second occasion.