Corey creates a Model of the Olive Branch

3D Photogrammetry of the Olive Branch – A Dive to Remember

Crewing a boat and setting up mooring lines comes with a lot of pressure—finding the wreck, blocking and lining it, and then setting the shotline so the boat operator can secure the vessel. This was exactly my task on the day I conducted 3D photogrammetry for the Olive Branch.

Finding the Olive Branch

The wreck sits south of Timber Island and can be tricky to reach except on the calmest of days. I’ve had about 11 dives on her over the past 20 years, with 8 of those in the last 3 years.

With Helen expertly maneuvering the boat, we used down imaging sonar to locate the wreck. After a few figure-eight passes, I sent the shotline down. Once geared up, I descended with my camera. The shotline landed just a few feet from the bow, making for an excellent start to the dive.

The Olive Branch sits upright in 95–100 feet (29–30 metres) of water. The mooring block lies 30–40 feet (9–12 metres) off the starboard bow. Visibility was moderate—on some days, you can see the wreck from the surface; on others, it’s hidden in darkness. On this particular day, the block was not visible from the bow.

I had hoped the mooring line would drop closer to the wreck, but luck had other plans—it landed 75 feet (23 metres) past the block. Out came my SMB (Surface Marker Buoy), and within 6 minutes, the mooring line was secured to the surface.

Photogrammetry in Action

As I made my way back to the bow, an idea struck:
💡 *The *Olive Branch* is relatively small—could I complete a top-down photogrammetry pass of the deck?*

I deployed my camera’s light arms, switched on the LEDs, and got to work. Five complete passes, carefully following a grid-like “mowing the lawn” pattern, covered the wreck:

• Four circular passes around the stern and deck
• Camera held steady just five feet (1.5 metres) above the wreck

Total dive time: 31 minutes
Bottom temperature: 45°F (7°C)

Back on the boat, my unusual swimming pattern caught everyone’s attention. Little did they know, I had just captured detailed footage that would soon turn into an incredible 3D model.

Rendering the Olive Branch in 3D

Once home, I dumped my GoPro footage and let my system process the data. After slicing the images, the final render took 8–10 hours on my water-cooled PC.

📷 Final model stats:

• 1,838 images
• 1,544,664 tie points

This was attempt #10 at photogrammetry, and I finally had a publish-worthy result! The detail captured in just 14 minutes of video was impressive, proving that meticulous filming makes all the difference.

🔗 View the final 3D model here:
🎥 Olive Branch – Sketchfab

🔗 Read more about the Olive Branch wreck:
📖 Shotline Diving – Olive Branch

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ShipwreckExploration #OliveBranchWreck #ShotlineDiving #MaritimeHistory #UnderwaterArchaeology #LakeOntarioWrecks #3DPhotogrammetry