There are days when you can't believe where you are, and this was one of them. We tore across the azure water towards an infinite horizon sandwiched between rolling folds of grasshopper green and foxglove pink. The sun baked our foreheads and the wind warmed our cheeks: Scotland in June masquerading as a wild Mediterranean. Behind us was the proud formation of the Isle of Arran; ahead, Loch Fyne and the promise of Portavadie Marina. My stepdad Nigel's RiB made light work of the water, flying gracefully over the waves.

Travelling from Lochranza on Arran to lochside Portavadie is most convenient by boat, taking only 30 minutes in the RiB to cover the around six-mile distance to an entirely different world. Hidden away on a promontory off Loch Fyne, Portavadie, which opened in 2015, is a luxury west coast retreat, comprising ultra-modern accommodation and Scotland's largest heated outdoor infinity pool. Later, as we explored the spa complex, it felt ludicrous to be venturing outside in nothing but our swimwear - but as our limbs sank into the deliciously warm, 33 degrees Celsius water, the sensation was heavenly. Beyond the pool edge, Loch Fyne shimmered as if scattered with crystals.

I'd have happily whiled away an eternity there, in this beauty spot to rival any I have ever seen, but the RiB and our onward journey to Tarbert across the water beckoned. Tarbert, dubbed the 'gateway to Kintyre', is storybook pretty - a collection of colourful cottages arranged around a horseshoe-shaped harbour. We munched cake, explored the irresistibly stocked Loch Fyne Gallery, and climbed up to Robert the Bruce's 12th-century castle, which boasted almighty sea views.

When we returned to Lochranza that evening, the sea loch slowly sinking into shade beneath the mountainous skyline of the 'Sleeping Warrior', we felt wind-battered, rosy-cheeked and entirely at one with the world. Scotland is such a heavenly concoction of surprises.