The first faint glow of dawn was just beginning to appear in the eastern sky as the armed cargo ship and its two destroyer escorts approached the deep waters of the Lombok Strait between the islands of Bali and Lombok.

Unknown to the crews, although perhaps strongly suspected, they had already been spotted by a Japanese long-range submarine. The strait was the principal transit route through the long chain of islands that formed the southern rim of what was then known as the Malay Archipelago, making it an ideal hunting ground.

Scuba divers visiting the region today follow in the footsteps of some big names. Ambon, on the northern edge of the Banda Sea, has been a favourite hunting ground for ichthyologists since the 18th century, and Alfred Russel Wallace spent a lot of time here during his 1854–1862 exploration of the region, a period during which he developed his ideas on biogeography and natural selection (independently of Charles Darwin) and came up with the notion of the “Wallace Line” that separates Asia from Australasia.

The Långban Gruva (Långban Mine) in the municipality of Filipstad in Värmland was opened in the 16th century and closed its doors in 1972. Located in Långbans Gruv och Kulturby (Långban Mining and Culture Village), the mine’s dive base is now operated by Långbans Dyksällskap (Långban Dive Club).

For the dedicated macro enthusiast, there are a number of locations worldwide that have gained legendary status, and the Philippines certainly has its fair share. Yet one had always eluded me: Romblon. Although I had been aware of it for years, the opportunity to visit had never arisen. My last trip to the Philippines, ten years earlier, was hampered by an international summit that closed Manila’s airport for days, thwarting a planned visit. Now, a decade on, my chance had finally come.

Last fall, my mother and I ventured to Indonesia in search of relaxation, diving and just spending time together. We chose two locations in North Sulawesi: Coral Eye on Bangka Island and Siladen Resort and Spa on Siladen Island, sister resorts that are special in their own ways, but mirror each other in service, luxury and commitment to environmental and social responsibility, plus excellent diving.

It was late evening when I rolled onto the ferry in Frederikshavn, Denmark. The hum of the engines and the salty breeze signalled the start of a long-awaited expedition. As the ferry glided towards Gothenburg, Sweden, I sank into my reclining chair, my mind drifting back to a conversation with a Norwegian diving friend over two decades ago. His tales of the fjords had sparked a dream, and now, I was chasing it.

The idea of the Azores has always conjured up images of dreamy, windswept islands of vivid green set against a backdrop of stormy blue waters. With limited knowledge of diving in the area, I had only heard of big animal sightings off Santa Maria Island during a very short season. But what about the rest? Isolated in the northeastern Atlantic, these islands had to be home to something spectacular, so I was keen to visit.

As a travel destination, Japan needs no introduction, famed for its history, scenery, cuisine and fusion of traditional culture and high tech. As a diving destination, however, it does not immediately spring to mind. Certainly, many are aware of Okinawa’s reefs in the country’s far south, but what about a flourishing dive scene mere hours from Tokyo, boasting a blend of temperate, sub-tropical and even tropical species?

It was a long, overnight flight from Amsterdam to reach Japan. The plane landed at Tokyo Narita Airport mid-morning. An intimidating monster-city of concrete, steel and glass, Tokyo had surprisingly clean and tidy streets dotted with several parks and green areas. Expecting my arrival, my Japanese son, Kirin Sekito, met me there, accompanied by his lovely 7-year-old daughter, all smiles. A professional underwater photographer and videographer, Kirin is a rising star in Japan, with many followers on social media. He would be my official guide for the next nine days on this dive trip.

The tiny, former volcanic island of Ustica, just 67km (34mi) north of Palermo in Sicily, has its roots dating back some 2.58 million years ago (Pleistocene). Included in the Aeolian Islands, which include Stromboli, Vulcano, Filicudi, Alicudi, Salina, Lipari and Panarea, there has been no volcanic activity for at least 130,000 years, but there is plenty of this former volcanism to be seen underwater, including pillow lava mounds, pumice blocks, domes and conglomerate, which have created some of the most incredible underwater scenery that I have had the pleasure to dive.