HMCS Cape Breton

A 440 foot World War II supply ship turned artificial reef

HMCS Cape Breton – A Massive Sunken Relic

The HMCS Cape Breton is one of the most impressive artificial reefs in British Columbia and a must-see for wreck divers visiting Nanaimo. Originally launched in 1944 as the HMS Flamborough Head, the ship later served the Royal Canadian Navy as a maintenance and workshop vessel before being retired in 1964.

In 2001, the Artificial Reef Society of British Columbia prepared the vessel for divers by cutting large access openings, cleaning hazardous materials, and creating safe internal pathways. On October 20, 2001, the Cape Breton was intentionally sunk near Snake Island, settling upright a hundred meters off the bow of the HMCS Saskatchewan and forming one of Canada’s most iconic paired-wreck dive sites.

At 134 m (440 ft) long and towering six decks high, the Cape Breton is the largest artificial reef in the Pacific Northwest. Its sheer size, towering superstructure, easy-to-navigate exterior lines, and flourishing marine life make it a standout site whether you're circling the outside, exploring the upper decks, or simply taking in the scale of the wreck from a depth your comfortable at.

Videos of the HMCS Cape Breton

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Recommended certifications and experience

The HMCS Cape Breton is a deep, expansive wreck with multiple decks and dramatic vertical relief, making it best suited for divers who are already comfortable at depth. While you can enjoy an excellent dive by staying on the exterior, the size and profile of the ship reward divers who have some advanced training and recent experience.

Most divers should meet the following recommendations:

Advanced Open Water (AOW) or equivalent: The Cape Breton typically sits in the 30–40 meter range depending on tides and your route. Confident buoyancy, descent control, and gas management are important at these depths.

Recent deep-dive experience: Having logged dives in the 28–35 meter range within the last season helps keep you sharp with buoyancy changes, air consumption, and narcosis awareness.

Nitrox certification (recommended): The wreck can be dived on air, but Nitrox 28–32% is strongly recommended. It increases no-decompression time, which is helpful given the Cape Breton’s height and the amount of structure to explore.

Optional but beneficial:

Wreck Diver training: Not required if you stay outside the ship, but helpful for understanding hazard zones, overhead awareness, and how to navigate large artificial reefs safely.

Solid buoyancy and trim: The site has areas of silt, soft growth, and tight swim-throughs on the upper deck. Good stability helps preserve both your gas and the wreck’s marine life.

These recommendations help divers get the most from the Cape Breton while keeping the dive safe, predictable, and enjoyable.

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HMCS Cape Breton dive profile overview

The HMCS Cape Breton offers a large multi-level wreck with plenty of exterior structure to explore and impressive vertical relief. The top of the wreck is often the best starting point, letting you work down the superstructure while staying clear of deeper areas unless planned.

Highlights you can expect to see:

- The towering superstructure and upper decks, now fully covered in plumose anemones
- Large open areas around the stern and bow, ideal for wide-angle photography
- Rockfish, lingcod, and perch sheltering along railings and cutouts
- Expansive metalwork that creates natural swim-throughs on the upper deck
- Seasonal clusters of nudibranchs, feather stars, plumose anemones and other invertebrates
- Dropping through the skylights and into the insides of the ship (if you're wreck certified)

Visibility & conditions:

- Best visibility usually runs September through March
- Spring and summer can bring herring spawn and algae blooms, reducing surface visibility
- Many days allow you to drop beneath the murky layer into clear green water
- Low-vis days can still be spectacular thanks to the fully extended plumose anemones

This wreck rewards slow, methodical exploration and offers different perspectives depending on tide height, visibility layers, and lighting on the day of your charter.

What to expect on your HMCS Cape Breton charter

Your trip to the HMCS Cape Breton begins aboard The Shepherd, our 35-foot dive vessel designed for comfortable and safe access to Nanaimo’s wrecks. The Cape Breton sits just a short ride from the harbour, usually 15–20 minutes, so the day moves smoothly and gives you plenty of time to focus on the dive rather than long boat transit.

Onboard, everything is set up to make big-wreck diving simple and stress-free:

- Seating for up to 8 divers
- A sturdy, easy-to-climb ladder for re-boarding after deeper dives
- Overhead netting for dry storage and crates under benches for gear
- A marine head (washroom)
- Experienced local captains who know the mooring line, currents, and the safest routes around the wreck

Most charters run on Saturday and Sunday, with weekday and private trips available if you want something more flexible. Typically, we’ll dive the Cape Breton first, enjoy a relaxed surface interval aboard the boat, and then follow up with a second dive, often the Rivtow Lion, Cape Breton’s sister wreck the Saskatchewan, or a classic reef site like Clark Rock or Snake Wall.