Penzance Harbour is small but extremely busy. Its mole protects a gaggle of fishing boats, pleasure craft, a ‘pirate ship’ of dubious pedigree and a boatyard which seems to produce spectacularly large motor yachts, judging by one unfinished hull nudging the quayside.

It is also the terminal of Scillonian III, the Scilly isles ferry which makes the crossing twice daily in summer packed with earnest travellers in hiking boots and anoraks. Increasingly, when round-Britain cruises are gaining in popularity, the Scillies appear on many an itinerary. So, when my son Mark announced that he, his wife and their dogs were taking me, my wife and our dog on a weekend outing to the islands, we jumped at the invitation.

Thus it was we found ourselves amid the anoraks and hiking boots, tramping up the gangway of Scillonian III, which looks much more like a mini-cruise ship than a ferry. The ship was packed; the only seats we could find were amidships with an uninterrupted view of the engine casing abaft the funnel. I took Jessie, our Welsh terrier, to the rail to admire the sea: she didn’t like it. Normally a fearless dog, she turned inboard, tail tucked between her legs.

I was flabbergasted, for she and I share the same taste in most things and I thought she would revel in being afloat. But no. She tugged me back and hid beneath the seat, where, it must be said, her cousins were also cowering. None of them, it seems, could be termed old sea dogs.

Leaving the family circle to investigate, I stumbled upon the Purser’s Office, a room of broom cupboard proportions. The Purser looked friendly. “Any chance of visiting the bridge?” I asked. To reinforce my request, I added I was thinking of writing a piece about the ship for World of Cruising. “I’ll ask the Captain,” she replied. “Come back in half an hour.”

I did, and she bid me follow her through a door on the boat deck marked ‘Private’. The Officers’ accommodation in which I found myself exactly replicated that of many ships of this vintage, albeit on a minute scale. We entered the wheelhouse, where the Mate was in conversation with the Captain.

“Make yourself at home,” Pete the Mate, said. At that moment, the Captain called from the wing: “Basking shark to starboard.” Pete’s broadcast over the PA caused a surge as every man and dog (except mine) crowded the rails to see the beast. Bishop Rock passed to port then fell astern as the smudges on the horizon hardened into islands. We rounded Peninnis Head, southernmost point of St Mary’s, then circled the Garrison into St Mary’s Pool, the little harbour of Hugh Town.

Scillonian III was alongside, the on-board crane discharging the containers of luggage (and backpacks) before the first of the new arrivals had stepped ashore. Mark had done us proud, booking us into The Harbourside, a mere 30 yards from the berth. We were installed in minutes; it was bliss.

And still only about 11.30am – two full days stretched enticingly ahead. Jessie was happy, too. The ground beneath her feet now stable, she was raring to go. And go she did. For two days we walked – the cliffs, the beaches, the ramparts. We visited pubs, dined royally of local fare, drank deeply, then walked some more. I began to see the wisdom of the hiking boots.

At one point, the going got too much for Jessie, and I carried her, over my shoulder like a sack of potatoes. It eased her pain, but did nothing for mine. But we loved it – the villages, scenery, atmosphere and ambiance which take one back some 30 years to a more tranquil time.

All too soon it was time to leave – but the resolve is there: we will be back. Many have loved these islands; Harold Wilson so much that he is buried here, and actor Jude Law, who waxes eloquent in the foreword to an island cookbook.

I can only agree. And I’m not surprised they now feature so strongly on cruise itineraries. I only hope the passengers who come in future will find their visit as rewarding as we did. Jessie still speaks of it – but makes no reference to the sea crossing.