THESE DAYS THE SOUTH PACIFIC ISLANDS are tropical paradise incarnate. Heaving with birds and insects, lush forests adorn their peaks, and coconut palms sway lazily over perfect beaches.
But many of these islands are volcanic in origin, the land now visible above the surface having been born fresh to the world from beneath the waves.
So how did all this wildlife manage to get here
For the Castaways film of our South Pacific series, we wanted to look at how life spreads out across the islands, so we travelled to the Solomon Islands, at the eastern corner of the famous Coral Triangle, to film some of the most diverse reefs in the Pacific.
This stunning archipelago of nearly 1000 islands is a place where myths and reality blur hazily together, and it is as fascinating for its cultures as it is for its wildlife.
The people here live close to the sea, and many tribes retain beliefs in ancestral animal totems, telling tales of elders able to call in the sharks and speak to the crocodiles. In some villages life has changed little in the past 100 years, and fishing on their bountiful local reefs is an important source of meat and sustenance.
There are beautiful reefs throughout the Solomon Islands, but for our filming we needed to go where the strike rate would be best, and decided on the Western Province.
At around 60 miles long, Marovo Lagoon is the largest saltwater lagoon on the planet, spectacular enough to have been dubbed by some the Eighth Wonder of the World. Offering spectacular diving, it will be the base for the first part of the shoot.

TRAVEL IN THE SOLOMON ISLANDS can be haphazard, to say the least. Boats and planes can leave early, late, or not at all, and roads are few and far between.
Fortunately, weve filmed here before so are prepared for this. Despite a few island-style hold-ups (a traffic jam caused by the capture of a large saltwater crocodile, debate about how much luggage the plane can take, and a lack of aviation fuel) we finally make it safely into the air aboard a slightly rickety-looking 12-seater aircraft.
Following the island chain, the little plane makes its way north on our two-hour journey, until eventually the legendary Marovo Lagoon comes into view. Bordering the island of Vangunu, the lagoons outer edge is semi-closed to the sea by a string of long, slim islets, separated by narrow passes to the outside ocean.
The lagoon itself is stunning. Dotted all over with tiny forest-covered islands and shallow reefs, and seemingly containing every possible shade of blue, it shines and sparkles in the Solomon Islands sun. Its so long that it takes about 20 minutes to fly from one end to the other.
Eventually, the strip of grass that is Ramata airport runway comes into view, and we make a bumpy landing. The airport is more of a hut than a terminal, and trolleys would be a non-starter on the grassy runway.
Our luggage is offloaded, and a small posse of locals helps us carry our 12 filming cases down a muddy path to the water. From here the only way on is by motor canoe, and we speed over the glassy water towards the small forested island where we will be based.
Waking up on the first morning were keen to get filming, but there are several possible sites, so it pays to do a bit of a recce. What were looking for is spectacular and diverse reef life, with lots of species of hard corals, and also sea-fans.
At the first site we visit were treated to the sight of a scalloped hammerhead cruising by in the blue, and quite a few good fans, but its mainly a wall site, and not exactly what were looking for.
Rounding a headland on our way to the next site, we come across a small pod of dolphins in a gorgeous sandy bay only a few metres deep.
Theyre playful, and catch the wake of our boat a few times, but theyre not that keen for us to get in the water and we move on.
Having checked out a few other sites, we settle down to film at an area thick with giant 3m fans just off the island on which were based.
The spot is at the outer edge of a channel, so when the current is flowing the fans spread to their full height to feed, and silver glassfish and colourful fairy basslets rise in clouds to grab particles from the streaming water.
Its an impressive spectacle, illustrating how the particle-rich waters fuel the reef food chain, so its a good start to the shoot.
Being in the Marovo is a real pleasure - water temperature is a very agreeable 29°C, and inside the lagoon its generally sheltered and calm. If it werent for the visibility - and the crocodiles - things would be pretty near perfect.
One downside of being in the worlds largest lagoon is that water clarity is very tide-dependent. Similar to the passes of oceanic atolls, the incoming tide delivers a flow of clear oceanic waters, but the vis can drop dramatically on the outgoing tide, as the murkier lagoon waters pour out through the island passes.
Weve taken this into account by visiting during neap tides, but still have to plan our diving accordingly, to maximise filming time.
The other downside is that some of this lagoon is crocodile habitat. Saltwater crocs can be found throughout the Solomon Islands, and there are reputedly some good, strong populations in the Marovo. The crew are all familiar with diving with sharks; croc-diving seems slightly less enticing.

OF COURSE, WEVE CHECKED into this already, and very few divers worldwide have ever been attacked. There again, not so many people actually dive in saltie country.
The prospect of meeting a croc seems slightly more real when we visit a local village and meet a woman who has had the lower half of her arm removed by a large animal. She survived, somehow, drifting the 1.5 miles back to her village alone in her canoe.
Then we hear of a snorkeller who was attacked on the very island on which we are staying. OK, so it was more than a year ago, and on the other side of our island, which is quite large - but there again, so was the croc, by all accounts.
Fortunately, local dive operator Grant Kelly is able to assure us that there has never been an attack on a scuba diver in the Solomon Islands. As he has been here for 15-plus years, diving almost every day, this is pretty convincing.
Good enough for the crew, we carry on. It would take a lot to keep us away from these reefs.
They are spectacular, with a multitude of coral and fish species crammed in side by side. Giant clams proliferate in the Solomon Islands, and although they have been hunted out in some areas there are still places where good clam gardens exist. Were able to get some nice shots of impressive metre-long clams, with pretty little blacktip sharks buzzing by overhead.
Lionfish also stalk the reefs in large numbers, and it turns out that close to the dock of our island they are in good supply.
Early one morning, cameraman Richard Wollocombe gets some spectacular footage of four together, hunting in just a few feet of water. Surrounded by tiny silver baitfish, and with their paper-thin fins catching the dancing morning light, the scene is entrancing.
Things are going well, but we still need to get some good wide shots of hard coral diversity, and with the visibility issues were finding it hard to get the underwater vistas were after. We decide were going to have to head out of the lagoon.
Penguin Reef is named not for its inhabitants, but for its discoverer, HMS Penguin, which came this way during wartime. Grant and Jill Kelly, our Marovo dive experts, guide us to its location. Lying outside the barrier reefs, were going to have to cross the entire width of the Marovo to get to it.
We speed over the glassy lagoon for almost an hour before taking a turn into an apparent dead-end inlet, surrounded by mangroves.
The engine slows to an idle and, as we ease our way along, we see the hidden opening to a narrow passage in the dense mangroves. The trees meet overhead, and the water is still and shady.
Its so shallow at some points that we have to stop the motor and use a wooden paddle to help us along. Gliding between the tree roots, this really does feel like crocodile country.
Finally, after about half an hour, we reach a wider passage, and emerge into the open sea.
The low-lying rocks of Penguin Reef are visible in the distance.

DROPPING IN HERE IS A JOY. The visibility is a good 30m, and the coral growth is dense and spectacular. The jumble of coral species is amazing. Large brain corals sit next to robust green elkhorns, fields of staghorns proliferate, and smaller branching and massive species reside side by side.
In between the corals, iridescent blue clams and giant kaleidoscopic cushion-stars add colour, and there are large patches of anemones, stacked with endemic anemonefish. The scene is a colourful tribute to the species diversity found in the Coral Triangle, and the increasingly rare sight that is a healthy, undamaged reef.
We spend the day filming, using as much time under water as our blood nitrogen levels will allow. Even our surface interval is spent floating passively with a mask, looking down on the wonderland below.
Eventually it starts to cloud over, and its time to head back. We pick up a school of dolphins as we near the entrance to the passage back through the mangroves - they ride our bow wave, and then disappear back to the blue.
I cant help but feel a little envious.