Zembra Island

Sidi Daoud · Nabeul Governorate · Tunisia

Zembra Island rises from the central Mediterranean like a fortress of limestone, its sheer cliffs continuing beneath the waves to create some of Tunisia's most spectacular wall diving. Designated a national park in 1977 and later recognised as a UNESCO Biosphere Reserve, this island roughly 15 kilometres north of Cap Bon has been sheltered from fishing pressure for decades, and the results underwater are extraordinary. I descended along the northern face of the island where the cliff drops vertically from the waterline into deep blue. Within seconds the wall was alive with colour: red and yellow gorgonian fans growing in dense profusion from every ledge, their polyps extended and feeding in the gentle current. At 20 metres, a dusky grouper the size of a large dog emerged from a cave and hung in the water column, studying me with the confidence of an animal that has never been hunted. Two more materialised from the gloom behind it, equally unfazed. The wall structure is riddled with small caves, chimneys, and overhangs that shelter lobsters, moray eels, and the occasional seahorse clinging to a gorgonian branch. I peered into one narrow crack and found a golden grouper wedged inside, its bronze flanks gleaming in my torch beam. Amberjack patrol the blue water off the wall, sometimes in schools of twenty or more, their silver bodies catching the light as they wheel past. As I ascended along the wall, the gorgonians gave way to encrusting sponges and coralline algae in the brighter shallows. Schools of damselfish and chromis swarmed the reef edge, and a small eagle ray glided past below me, disappearing over the drop-off. The visibility was staggering, easily exceeding 30 metres, and I could trace the wall curving away into the distance in both directions. Zembra delivers the kind of pristine Mediterranean diving that most people assume no longer exists, a time capsule of what these waters looked like before overfishing stripped them bare.