From hidden coastlines to secret reefs, there are plenty of dive spots that fly under the radar. Whether you're visiting Indonesia's remote Halmahera Island - home to walking sharks and spider crabs - or diving into the unspoilt waters of Tanzania's Mafia Island, wonders await beneath the surface in hidden corners of our oceans. Intrigued? Read on to uncover our roundup of the most underrated diving destinations...

Diver in the Banda Sea

Banda Sea, Indonesia

Indonesia's Banda Sea is kicking off our list of the most underrated diving destinations. Stretching from Ambon in the north to Alor and Maumere in the south, the Banda Sea is home to vibrant swaying sea fans, hard corals and myriad marine life (think hammerheads, mantas and sea snakes). The 11 largely untouched Banda Islands sit right in the heart of the Coral Triangle, meaning they're surrounded by pristine reefs.

'I've only just fully understood how remote and diverse this destination is,' said one of our Original Diving experts after a recent research trip to the Banda Sea, 'most of the dive spots are only reachable by liveaboard and very few people have heard of them.'

Reef scene in Halmahera, Indonesia

Halmahera, Indonesia

Sticking with Indonesia, we think Halmahera is another underrated diving destination, particularly for dive newbies. Sitting pretty between the Lembeh Strait and Raja Ampat, this lush volcanic island is surrounded by gin-clear waters and healthy reefs, making it ideal for beginner divers.

The island is largely untouched, boasting vibrant coral slopes and plenty of muck diving opportunities. Though historically under-researched, Halmahera is teeming with sea creatures - from the famous Halmahera walking sharks (Hemiscyllium halmahera) and spiky spider crabs to humpback whales, orcas and dolphins.

Mafia Island, Tanzania

Mafia Island, Tanzania

Next up: Tanzania's Mafia Island, an unspoiled alternative to busier Indian Ocean spots around Zanzibar and along the coast. Almost all Mafia's best dive sites lie within Mafia Island Marine Park and are at depths of less than 30m (paradise for sports divers), and the reefs are home to over 460 fish species. The real highlight? Whale shark encounters. The nutrient-rich waters around the archipelago attract these gentle giants, especially between November and April.

'On my last dive in Mafia Island, I saw a guitar shark,' shared one of our Original Diving experts, 'it's an extremely rare sighting and I witnessed it on a shore dive, after spotting dozens of tiny macro critters'.

Hammerheads

Curacao, Caribbean

Curacao, part of the Dutch Caribbean, is another under-the-radar dive spot well worth a visit. Just north of Venezuela, it boasts a variety of easy-to-reach shore dive sites, like Playa Lagun, Playa Kalki and Cas Abao, where colourful coral gardens await. Or head out by boat to sites like Watamula, with its mushroom-shaped coral heads, and Porto Marie, home to a double-reef system. According to one of our experts, dives here can bring all sorts of surprises, from lone hammerheads and manta rays to large tuna. With great visibility and calm conditions, Curacao is easy to explore.

Portugal, Azores, Santa Maria

The Azores, Portugal

If you're looking for an underrated dive destination closer to home then the Azores rounds off our list nicely. While many divers look long haul, the Azores boasts a mix of local and offshore sites. Spots like Formigas, Dollabarat, Princess Alice Bank and Ambrosio are well worth shouting about if you're keen to spot mobulas, mantas and sharks. Just keep in mind, that due to their depth and currents, these sites are best suited to experienced divers, with Advanced and Nitrox certifications recommended.