Robinson Crusoe would be incredulous, appalled, perhaps slightly envious. I’m stranded on a teardrop of bleached sand and viridian jungle in the Indian Ocean where, shaded by a parasol above a padded recliner, I’m wearing a cream bathrobe and monogrammed slippers, my feet resting on a Moroccan pouffe. I’m cradling an iced beer. The main danger isn’t dehydration, starvation or snakes – it’s tripping over soft furnishings.

Castaway life, as reimagined by, say, Ralph Lauren, is an optional excursion at W’s cool contemporary Maldivian resort. Just a mile away across the deep cyanic sea, its tiny satellite, Gaathafushi Island, offers a photogenic hit of serenity, soliloquy and sublime nature without another human to sully your pristine beach. It’s not my first “shipwreck”. Two decades ago, I was helicoptered onto a deserted speck of granite in the Seychelles – now North Island, the epitome of barefoot luxury – as a guinea pig for an extreme outward-bound experience. I was allowed a Swiss Army knife and, following SAS advice, condoms for emergency water storage: a recipe for a week of hunger, sleep deprivation and relentless mosquito bites, many in places you wouldn’t scratch in public.

Gaathafushi promises to be a little different. The two-night adventure begins aboard a traditional wooden dhoni on W’s regular staff fishing trip. Serenaded by boduberu drums, we plan to mine a generous vein of grouper and snapper above a neighbouring reef. I may be a grizzled castaway veteran, but I don’t get a bite. I’m the only person not catching. Next to me, the resort’s spa therapist, with coiffured hair and manicured nails, lands one beauty after another. It knocks the confidence. Cue flashbacks to early attempts at spear-fishing in the Seychelles where a rogue wave shredded my Speedos and washed away my contact lenses, leaving me naked, myopic and constipated on a diet of unripe mango.

Not this time. A new reef changes my fortune. I disembark on Gaathafushi with enough snapper to sate a ravenous dinner party. Flaming torches illuminate the magnificent beach: a dramatic setting for a B-movie sacrificial ritual. Or grilling fish. At least I’ll see what I’m chewing. My first tiny fish supper on North Island, on day four, tasted fleshy then crunchy.
I’d eaten the fin. Then rubbery. I’d eaten the eye. Cooking also promises to be a tad more Masterchef. Forget scratching flints for a spark, W has suspended a grill plate over a pre-prepared fire pit, with matches, olive oil and lemon juice, alongside foil-wrapped potatoes and sweetcorn, garlic bread and professional kitchen utensils.

An ice box chills beers and still or sparkling mineral water – castaways can be so fussy about hydration – and a picnic rug is laid with cutlery, a coaster and wine glass. By the tamest explorer’s standards, it’s soft, decadent even, but sitting alone on my island, nibbling fresh fish under the star-slathered heavens, Gaathafushi feels remote, wild and primal.

A night of tomb-like sleep and I awake to a poetic sunrise. A crimson line marks the horizon at the exact level of the beach’s single parasol: a perfect fusion of design and nature. Kevin McCloud would adore W’s open-sided pavilion, cooled by trade winds. At dusk, cream-coloured mosquito nets roll down, backlit by glowing lanterns. Its vast sumptuous bed, cocooned in white linen, is paired with rustic rugs, while a bathroom, tucked back into the trees, has a shower, flushing loo, fluffy towels and lemon and sage Bliss toiletries: the sweet-scented call of the mild.

It is, I can’t deny, far superior to my North Island A-frame shelter with palm-frond walls and ant-infested earth floor. Attacked by hornets during construction, I provided a feast for mosquitoes at night. Sleep was near impossible. By day four I had more than 200 bites – castaways are time-rich, repellent-poor – perhaps double that number by the weekend. Eyelids, ears, buttocks, everywhere was blitzed. Gaathafushi’s bug juice and insect coils are absolute saviours.

Days rapidly assume a tropical languor: a morning skinny dip and sunbathe followed by a shady retreat from the equatorial heat, observing as the ocean mutates from emerald to Prussian blue under the midday sun. The silence is deafening, punctuated by the putter of tuna boats and heavy slap of pelagic predators chasing smaller prey.

As lethargy guilt sets in, I circumnavigate my island. It takes three minutes: a route of dazzling beach, then palm and mangrove, ending on a triangular sandbank where I’m divebombed by angry terns. Swimming doesn’t take much longer. A 14-minute front crawl and I’m back where I started. Gaathafushi is a petite paradise.

It also wears a striking coral necklace beneath translucent shallows. W’s snorkel reveals technicolour tropical fish, green-eyed squid and the occasional barracuda. It’s thirsty work. Back onshore, I reach for an iced Coke, a stark contrast to North Island, where locating fresh water involved a 45-minute trek to an old farm well, following a jungle path boobytrapped with falling coconuts and vast spider webs. My water, stored in condoms hung from a branch, quickly acquired a disturbing tang of lubricant.

It’s not my worst memory, however. Late in my stay, hunger drove me to butcher a wriggling octopus with a blunt penknife – an act that still reappears in anxiety dreams. There’s no such trauma on W’s private retreat. Two surprise speedboat deliveries include breakfast of smoked salmon, fruit and patisseries, and a supper of tiger prawns and lamb chops. I will not lose eight pounds as I did in the Seychelles.

Yet for all its opulent flourishes and the safety net of a two-way radio, Gaathafushi still offers gloriously isolated, gentle adventure. Back at W’s mothership, I recline in my overwater villa’s pool, cocktail in hand, and contemplate my second, radically different castaway escape: another world just a mile away.

10 full-board nights at W Maldives, including overnight on Gaathafushi, Emirates flights and transfers from £20,505; destinology.co.uk