If there is one thing better than a holiday on one beautiful Caribbean island, it is a holiday on two. That is exactly what a Somerset-based company is now able to arrange – and you won't find two more lovely isles than Grenada or Bequia.

The latter is one of those magical places that haunts the imagination of those who dream of sailing in tropical seas. Bequia has long had a name for its hand-built boats and its skilled seafarers – and the fact that its seven square miles also happen to be sensationally scenic means that this green jewel can float in the imagination like some emerald vision of Caribbean perfection.

At least, that's how thoughts of Bequia (pronounced Beckway) have been for me – I first heard of the island some 25 years ago, but the place is not exactly on the tourist map and few tour operators are set up to oblige. So, despite a quarter of a century of yearning, I'd never been.

Not surprisingly, the island's off the well beaten-track status has paid dividends – indeed this is how Frome-based travel experts Just Bequia introduce the island: "It stands as a reminder of how the Caribbean was 50 years ago, when only a few visitors ventured this far."

The same travel company also operates a longer-established branch of its business called Just Grenada, so it's only fair that we quote its blurb too: "Why Grenada? Because it is one of the loveliest of the Caribbean islands and offers a huge variety of things to do and see."

For the first time this year the company is offering a single package to both islands, which turns the whole trip west across the Atlantic into an altogether bigger, more alluring, adventure.

When I tell you that our holiday included a connection in a privately chartered aeroplane that island-hopped at low altitude up along the stunningly beautiful Grenadine archipelago, you'll see what I mean.

This most exciting of tropical vacations begins in Grenada, which I'd recommend to any first-time Caribbean traveller looking for an island to encompass all that is best, most atmospheric and at the same time picturesque in that sun-blessed region.

Grenada is largish island, and just about every acre of it is sensationally beautiful. Moreover, it has not been spoilt by the kind of in-your-face tourism that has overtaken so many of those distant isles.

Apart from being fantastically scenic, the reason I'd recommend Grenada to a first-timer wanting to experience an authentic taste of the region is that it is wonderfully friendly and relaxed. Which begs the question why it hasn't been invaded by massive hotel chains offering cheap, all-inclusive deals, and also has you wondering how long it will stay unspoilt.

The large, mountainous 133 square-mile island was a British colony from 1763 to 1950, so English is spoken by the 110,000 residents – but it's the more recent history that may have, for a short time, slowed Grenada's development as a tourism destination.

Not that the US intervention, which made headlines in 1983, is in any way evident today – the political shenanigans that needed a quick emergency fix nearly 30 years ago are distant history.

As for the hurricanes which can blight much of this region, Grenada is south of the main risk zone, so for the most part remains happily becalmed – though a bad one did hit in 2004 and you can still see evidence of it today. The agricultural industries, including the all-important nutmeg and other spice groves which gave the place its Spice Isle nickname, were badly hit and there is much replanting going on across the rain-forested mountain slopes today.

You can find out more about the fascinating story of nutmeg if you visit somewhere like De La Grenade, a business that specialises in producing value-added items based on the fragrant flavour of the actual flesh of that remarkable fruit. For example, it makes a delicious syrup from the material which surrounds the nutmeg and its mace – a fruit flesh which is normally discarded.

We learned about this, and much else, in the company of charming and informative Arnold Hopkin, who owns the Blue Horizons Garden Resort. Arnold is a great expert on all things Grenadian – indeed he drew us up an excellent itinerary which we followed in our four-wheel drive hire car to all corners of the green and sceptred isle.

Blue Horizons, which boasts luxurious accommodation in 32 cottages, nestles among lush tropical gardens that are home to 21 species of indigenous birds, and is situated on a hillside just behind Grand Anse Beach, which is the largest sandy strand on the island.

Guests at Blue Horizons can gain access to the shore by walking through the five-star Spice Island Beach Resort, owned by Arnold's brother, Sir Royston – and yes, if budget allowed you might prefer to be right on the beach in this most luxurious of establishments. But we enjoyed the laid-back atmosphere at Blue Horizons at a much lower cost, though did manage to book a memorable multi-course dinner at Spice Island's beachside restaurant.

Grand Anse Beach is at the southern end of a large bay, and across the blue waters you can see the capital, St George's. This fascinating, busy, town is well worth a visit – it is friendly and exudes the authentic charm of Caribbean life in all its steep streets.

The market square is the frenetic and happening place – loud and slightly anarchic, and you have to be ready for the hustle because local traders don't see so many tourists since a posh new air-conditioned cruise liner centre was built across the road. Apparently the cruise-folk don't bother coming into town for a taste of Caribbean authenticity now that they can buy a few souvenirs in the cruise terminal.

We bought some local crafted jewellery, which did the anti-hustle trick because the stallholder showed me where I could buy a fresh-made roti (a kind of Caribbean curry-filled pasty) then let me take her seat – and while I dined like some Del Boy far from home she kept the more pushy hawkers at bay.

I'd also recommend a quick visit to the island's museum, which you'll find in the heart of town – not only will you learn about the early indigenous inhabitants who have long since disappeared, but you'll see evidence of Grenada's many and various colonisations. There's also a small and charming restaurant serving local food attached to the place – though you'd never find it passing by on the street.

After a couple of days acclimatising at Blue Horizons, we headed north up the west coast. Halfway up the long and winding road we made a detour so that we could hire a local guide and hike up to Fountainbleu Falls, high in the rainforest. It was hot and sweaty work, but fascinating if only for the amazing plants along the way – a sort of long, near vertical, stroll through Kew Garden's hothouse.

Our eventual destination that day was the very tip of the island, where an English couple called Philip and Annie Clift have built and developed the dreamy Petite Anse resort.

What can I say about this boutique hotel set in beautiful tropical gardens with sweeping views over the Caribbean to the neighbouring island of Carriacou and the Grenadines? Well, put it like this – when my novel writing finally pays dividends with some kind of Hollywood deal (in my dreams) it's to Petite Anse I shall go when the British winter gets too cold and wearisome.

The views, the style and charm, the ambience, the sounds of the rainforest, the crash of the warm sea, the cooling scented inter-island breeze…

No, I must stop Caribbean dreaming and return south, via the pretty little town of Sauteurs, which is where the last of those poor indigenous folk called Carib Indians chose, en masse, to fling themselves from a cliff-top rather than become enslaved by Spanish invaders.

Our journey back down the island took us to the east coast, past chocolate factories and rum distilleries – and at the totally untouristy seaside town of Grenville we pointed the car inland to climb over the central mountain range and its Grand Etang Forest Reserve.

At 2,500 feet you might think you'd come across a cool breeze – especially up there in the high forests where lakes fill old volcano craters – but no, this is the tropics, and in these latitudes even mountains stay hot.

Back down in the south – which is the most populated and developed part of this mainly rural island, we stayed at the True Blue Bay resort, which is undoubtedly a great favourite with Grenada's big sailing community. It's a comfortable and friendly place and obviously ideal for those with chartered boats parked in the adjacent marina.

It's also fairly close to the airport, which is where we went early next morning for our flight to Bequia. I had been warned that this was going to be a treat – the 25-minute flight takes you right up through the Grenadine Island chain, passing impossibly romantic places like Mayreau, Tobago Cays, Palm Island, Canouan and Mustique along the way.

But first our little Island plane dropped off two local passengers at Carriacou before heading north across the dreamy isles mentioned to arrive at the green, green jewel of Bequia.

From the small new airstrip we were taken by specially adapted pick-up truck – which is the ubiquitous form of public transport on this island – to the wonderful and luxurious Bequia Beach Hotel, where I could happily have retired from journalism and just about everything else forever.

The resort is set on the slopes of the hills which run down to palm-strewn gardens and a beach. Friendship Beach to be exact – which has now entered my list of Top Ten beaches in the world. Think warm seas washing soft sand, shaded here and there by dramatically drooping trees and punctuated at one point by the hotel's bar and excellent restaurant.

It wasn't the busiest season when we were there, and the only things we shared the beach with were pelicans and crabs. When the heat got too much, our large, air-conditioned, sensationally decorated apartment was a stylish refuge if ever there was one.

A complete island tour took just three hours despite the fact that we never went above 10mph – and included stops at different altitudinous viewpoints, visits to wild beaches tucked beyond mighty palm groves, and a fascinating tour around Bequia's turtle rescue centre.

There are about 5,000 Bequians – they're of African, Scottish, Irish, French, Indian and Carib descent – and English is the main language spoken.

I'd heard that these islanders have an open friendly attitude to visitors, and it is true – you can experience the full and jolly brunt of it if you spend a morning or afternoon in the tiny capital Port Elizabeth.

Nothing much happens save for the comings and goings of the St Vincent ferries, as well as the pick-up truck taxis – there's a small market, quite a few intriguing shops and the general laid back buzz that somehow pervades the numerous restaurants and eateries where you can order all manner of Caribbean foods and dishes. I went for conch salad – which was excellent in a chewy kind of way.

And Port Elizabeth – like all of Bequia – is beautiful to look at. Sublimely, dreamily, enticingly, beautiful. As you sit there sipping a cooling cocktail it is easy to think that this is the best location for a holiday in the world – until you remember the happy fact that you are not tied to just one destination.

With the Just Grenada, Just Bequia option, you get two for your money.