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Dive Site Guide · Marine Encyclopaedia
A guide to diving with Cape Town’s local marine life
Danel Wentzel·6 November 2025·14 min read

When you think about scuba diving, usually the first image that comes to mind is diving in warm tropical waters, hovering over coral reefs. But have you considered there might be an even more colourful dive site out there, teaming with life?

Along Cape Town’s shores, there lives a world beneath the waves. From the surface, kelp forests just look like floating, slimy plants, but once you submerge underneath, you will see an alien landscape come to life. In these kelp forests live over 14 000 documented species of marine animals.

Cape Town is one of the largest cities in South Africa and among the most multicultural in the world, uniquely situated on the tip of Southern Africa between the Atlantic and Indian Oceans. The Atlantic brings cold water up from the icy poles; the Indian brings warm water down from the Mozambique channel. The meeting of these warm and cold water masses has created a vast diversity of life underwater.

Kelp (Ecklonia maxima), also known as sea bamboo, form underwater forests rising up to 15 m from the sea floor. They create a unique habitat to explore, acting as a refuge for smaller species of reef fish and shysharks.

Tips for marine life-spotting

You have all the gear ready, mask, snorkel, fins and wetsuit packed. Now what? Here’s how to spot the kelp forest locals.

01
Check the diving conditions. Just like weather on land, the ocean changes daily. Apps like windy.com help predict the best days to explore.
02
Research your dive site. From cold-water corals home to 80+ nudibranch species, to thick kelp sheltering 13+ shark species, different creatures live in different habitats.
03
Pick up a field guide. Browse the common species before you take the plunge. My favourite is the Two Oceans Guide.
04
Slow down. The kelp forest is full of camouflaged critters. The slower you swim, the more you’ll spot waiting for you to pass by.
05
Get low. Swim close to the bottom and scan the top of the reef line to catch sneaky fellows like octopuses slinking away.
06
Ask a local divemaster. They know where the resident critters live, mention what you hope to see, and you’ll support local eco-tourism too.

Cape Town’s common endemic marine life

On a single dive you can spot octopi, crustaceans, sea fans, sponges, feather stars, brittle stars and fascinating fish like the klipfish (34 species described here, most of them endemic). The kelp forest also shelters several small sharks, catsharks and shysharks, using the kelp as refuge from larger predators.

Cartilaginous fish
The sharks & rays
Pyjama shark
A small but mighty catshark of the kelp forests, named for its cosy striped pattern. A skilled hunter that can curl its slender tail into a doughnut to hide in tight spaces.
Puffadder shyshark
A master of camouflage, its golden-brown saddles echo the puffadder snake. Non-confrontational, it curls into a doughnut when threatened.
Short-tail stingray
A large, impressive ray with a flattened disc-like body that blends into the sandy floor. Its venomous barb is for defence, but it would rather swim away than use it.
Bony fish
Three awkward, wonderful favourites
Red roman
A vibrant red body flecked with white spots and sharp teeth for crushing crustacean shells. Listed ‘orange’ on the WWF SASSI list, think twice before buying one.
Galjoen
South Africa’s national fish, declared in 2010. Tough and adaptable, it can change colour to blend into the rocky reef of the turbulent shoreline.
Longsnout pipefish
Often mistaken for a seahorse, this slender fish has a long snout for hunting tiny crustaceans. As with seahorses, the male carries the eggs, wrapped in his tail.
Mammals
The giants & the playful

Over 40 marine mammal species depend on South Africa’s waters. The seas near Cape Town support the widest diversity, five dolphin species and three baleen whales, where the cold Benguela meets the warmer Agulhas current.

Cape fur seal
Agile, social and playful. The colony swells past 74,000 in breeding season, with around 20,000 pups, and a remarkable delayed-implantation pregnancy.
Common dolphin
An hourglass-flanked acrobat travelling in synchronized pods of up to 1,000, the engine of the sardine run.
Humpback whale
The ocean’s acrobats, breaching, lobtailing and spy-hopping. They gather off Cape Town in the largest humpback super-pods known on Earth.
Southern right whale
A baleen giant up to 17 m, here June–November to mate and calve. Once near extinction, now a breaching, tail-slapping highlight of the Western Cape coast.
Dusky dolphin
A small, highly social oceanic dolphin in pods of up to 100, leaping and somersaulting, diving to 200 m for fish and squid.
Invertebrates
The strange and spineless
West Coast rock lobster
The local crayfish, up to 60 cm and 4 kg. Known to walk ashore to escape low-oxygen red tides.
Krill
Tiny crustaceans, the reason the whales are here. They swarm in densities of up to 10,000 per cubic metre, the link between plankton and giants.
Common octopus
Eight arms, nine brains and blue blood. A shape-shifting, colour-changing escape artist, and brilliantly clever.
Common cuttlefish
A colour-shifting cephalopod with three hearts, blue-green blood and an internal cuttlebone you’ll find washed up on the beach.
Nudibranchs
Dazzling sea slugs, over 220 species described here, new ones still being found. Toxic, hermaphroditic, and impossibly colourful.
Sea urchins
The spiky Cape urchin grazes algae and keeps the reef healthy, harmless to humans, and a delicacy in some cultures (‘uni’).
Abalone
An iridescent-shelled mollusc, sadly poached to near extinction. Choose farmed abalone, never wild, to protect the species.
Sea stars
The African spiny sea star, our only carnivorous one, keeps the ecosystem in balance by preying on molluscs, crustaceans and other stars.
Corals
Soft corals and sea fans thrive in the cold Cape water. My favourite, the resilient false coral, shelters small fish and invertebrates.

In conclusion

Cape Town is a treasure trove of marine biodiversity. From majestic whales and playful seals to colourful fish and intricate invertebrates, the ocean here is a wonderland waiting to be explored, and we’ve only touched on the most common of countless creatures in these waters.

Freediving, snorkelling and scuba diving are all wonderful ways in, whatever your experience. If you’re new to the underwater world, start with snorkelling or a guided dive.

But remember, the ocean is a fragile ecosystem that needs our protection. Say no to single-use plastic, walk or cycle where you can, and switch off the lights behind you. Every bit counts.

So grab your wetsuit and dive into the fascinating world of Cape Town’s marine life. You never know what you might meet beneath the waves.

Want to explore this hotspot for yourself?
Come dive Cape Town’s kelp forests with me. Guided dives for every level, where you’ll learn to read the ocean like a biologist.
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