Defence Islands

Photo: Sea Kayak Association of BC

Porteau Cove, Photo: Sea Kayak Association of BC

By Stephen Pearce. Another installment of our series on scuba diving near Vancouver. This time Stephen explores Defence Islands.

SpongeBob’s ultimate fantasy…

Imagine soaring over ivory towers, parapets, walls and cities – majestic, beautiful, awe inspiring – and all made entirely out of delicate sponges!

Welcome to the stunningly beautiful underwater landscape of Defence Islands.

Defence Islands are two small islands in Howe Sound easily seen on the far horizon from Porteau Cove on the Sea to Sky Highway. Both are under the administration of the Squamish Nation. And both are only accessible by boat.


Captain Marc Palay from New World Diving gave me and a few lucky partners the opportunity to explore this site as a potential location for future divers. And we jumped at the chance.

We had some idea of what to expect but we weren’t quite prepared for the surreal landscape. A reef covered in colonies of silica-based glass sponge – some old and some very new – at a depth of about 33 meters. Usually life like this would only be found at much deeper levels beyond the reach of recreational divers.

And buttressed against the colonies of sponge was a forest of sea whips – slender stalks of long delicate coral with dozens of polyps – flower-like appendages – each with eight tentacles to catch and consume plankton and particulate matter.

Both the sea whips and the sponges are animals – the simplest of multi-cellular creatures – and both are a testament to the quality of the water in Howe Sound. Without organs, a brain or a central nervous system, sponges work all day cleaning the sea of particulate matter by filtering as much as 378 litres in a single day. That’s pretty impressive for such a simple creature.

We moved slowly and silently through the kingdom; careful not to disturb the delicate ecosystem. But all too soon we had to reluctantly make our way back to the surface. Marc was waiting for us topside and could tell from our excitement that we had found someplace pretty special.

SpongeBob would have been proud.

Photo: Stephen Pearce

Photo: Stephen Pearce

The dive is recommended only for experienced divers due to depth and the need for excellent buoyancy control. A light, and a backup light, is essential.

New World Diving ports out of Horseshoe Bay and can be contacted anytime at

Safe diving.

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