Gourmet picnics on deserted islands, cyan waters and coral reefs teeming with marine life made Fishfan feel like a reincarnated Captain Cousteau when diving on Pemba Island

The 35-minute half-empty flight yielded picture-postcard aerial shots of uninhabited islands and the reefs, before touching down in Chake Chake on Pemba Island, Tanzania, half-way up the west coast at the end of a long mangrove-lined creek. The airport was a small ramshackle affair, and despite a plethora of attractions including atmospheric ruins, primeval forest, unique bird species, deserted beaches, and some of the best diving in the Indian Ocean, Pemba probably hosts less than 100 tourists at any given time.

Before heading off to one of the three resorts on the island, it’s well worth having a look around Chake Chake and its crumbling buildings and stall-filled alleyways, taking in the fruit and vegetable market, trying out the sticky paste made from tamarind, ginger, sugar, nutmeg, and cloves, and watching the grazing hump-necked cows interrupt an impromptu football match in front of the mosque.

Swahili Divers and the Kervan Saray eco-resort on the northwest coast are run by Farhat Jah, a seemingly eccentric mixture of Turkish and Indian heritage with a resolutely British upbringing, and his Dutch wife, Cisca. Known by locals as Mr. Raf, and just Raf to anyone else, there is something of a young Basil Fawlty in him that, whilst a little surprising initially, is ultimately endearing.

The accommodation was built in 2008 from local materials, and the quarry where the bricks were cut is, well, a stone's throw away. Any imported goods come by dhow whose carbon footprint is limited to the fire that the crew use to warm their food at night when at sea. It is the best priced on the island with dorm beds and doubles, and good value packages. Food is wholesome and filling, and is locally-sourced and cooked with love by Chef Mzee Ali on charcoal (chocolate biscuit cake a speciality), unlike the other two resorts that ship most supplies in, and is the most affordable Pemba diving option.

Raf pioneered much of the diving from Pemba, and has discovered many of the sites himself, hence the odd names. You'll find no Aquarium here. Deep Freeze, Slobodan's Bunker (after the ex-Serbian warmonger), Le Reef Caché (hidden reef in French) and Emilio's Back Passage to name a few. With a wealth of knowledge of the reefs and conditions, years of experience, and a passion for underwater photography and videography, and you can pick up a host of tips from Raf, provided you can keep up.

The RIB zipped across the top of the flat sea, taking us to Deep Freeze. The ride had been soothing, re-enforcing the remoteness of this small island 50 kilometres off the coast of one of the poorest countries in the world. We passed locals in sailing dhows or dugouts, fishing teams of up to ten men swimming nets into a circle, slapping the water to scare fish into the net. Now it was time to see if Pemba lived up to its growing reputation.

Looking down as we kitted up, the table corals twenty metres down were clearly visible. Backwards roll, hot tub, OK, going down. Equalize, all together? Look around. W-O-W. With a capital W. On one side was a wall, like the top of a submerged mountain, covered in corals of all descriptions, teeming with fish. On the other, the bluest blue, near perfect viz, dropping down, and down, and down. Lucky there's no point talking underwater, because I was speechless.

The surface interval snack of still-warm crepes was taken on a deserted island of fossilized coral and white sand before heading off to Slobodan's Bunker, best described by looking down on your hand with digits splayed, each gap a ravine in the reef full of marine life.

The following day, at Le Trek, we spotted a six-metre wingspan Manta, accompanied by the largest and ugliest old cobia I have ever laid my eyes upon. She glided by on the outside to the edge of visibility, then turned, slowly soaring back, under me and up over the group.

Maybe it's a mix of the remoteness of the island, the remoteness of Raf's sites, and a touch of melancholy from sitting at a keyboard, but the diving here felt like real adventure, as if all I needed was a red woolly hat and I was the re-incarnation of Commandant Cousteau.

The next port of call was The Manta Resort on the northeast tip of the island. Built on a hill just up from the beach, The Manta Resort’s well-appointed rooms go from between 245 (village rooms) and 445 (Sea Front villas) euros for a double, full board (excluding dives).

Dives were broken up by gourmet picnics on tidal sand islands in cyan waters under cloudless skies. It was blissful; more dream diving. Then it was time to move on for the last stop of the trip at luxurious Fundu Lagoon down south.

I couldn't hope to top the past week's diving, but the place itself looked impressive on the web, and the room rates certainly were at 660 USD a night per standard double, all inclusive (excluding champagne). After a 70-dollar taxi ride back to the airport, I met the Fundu transfer minibus and three well-heeled guests. 45 minutes later the driver dropped us at Pemba's main port of Mkoani where a speedboat was waiting to whisk us to the lodge, a 10-minute ride away.

The long wooden jetty was impressive, as was the discreet but warm welcome. The rooms are large safari tents inside a wooden cabin, with a magnificent en-suite shower room, complete with Fundu Lagoon's own range of four shower gels and shampoos (one of each for the morning and the evening, obviously), and a secluded bit of beach for each of the 16 rooms, the more expensive suites having their own pool too. The sunset views over the infinity pool and across the bay were breath-taking, and the sun setting directly behind the jetty bar and into the ocean surreal. It being a Saturday, dinner was being served on the beach, an eat-till-you-burst gourmet braai of lobster, tiger prawns and calamari washed down with excellent French wines and a few forgotten cocktails for desert.

The next morning a cocktail of all four gels and shampoos revived me enough to make it down to the dive centre. The water was like a mirror, as we sped across to Misali Island and its surrounding reefs for my two last dives on Funga Pacha and Coral Mountain. Six of us baled over the side and dropped down to 18 metres. More clear blue water, more prolific fish life, and on the last dive, the magnificent marbled cleaner shrimp, and a last sighting of a crocodile flathead with a lionfish and a Model Toby in the viewfinder. More stunning coral.

Pemba had been awesome. It's not a place for "big" encounters every dive, but the variety and volume of small to medium-sized species is outstanding.