About

Lock 21 has been underwater since 1958. It is at Dickinson Landing, one of the Lost Villages of the St. Lawrence, flooded when the Seaway opened. Its walls lie 40 feet (12.2 m) below the surface and its floor at 60 feet (18.3 m). I set out to digitize the whole structure in 3D, zone by zone, dive after dive, with photogrammetry.

This site is the field notebook of that survey: what I did, how I did it, and what came out of it.

What it is for

Showing the lock to people who don’t dive. Few people will ever see it with their own eyes: it takes a dive to 60 feet, in a canal with a strong current. The 3D model can be explored in the browser, on a computer or a phone. It can also be placed on a table in augmented reality, or opened in Google Earth at its real location.

Helping divers plan their dives. The site zones page describes the lock’s 25 zones, and the page on the current in the canal tells divers what to expect. The 3D model lets you find your way around and check depths before getting in the water.

Documenting the method. Underwater photogrammetry is learned by getting it wrong. I write everything down so that other divers can do it elsewhere:

• the gear and its settings;
• the dive log;
• the processing, from extracting the photos to the model;
• the problems encountered and the solutions found (see the menu).

Where the survey stands

The survey moves forward one zone at a time: the 3D model page shows how many zones are online, and the progress tracking gives the state of each one. The site grows with the model.

Who

This survey is a personal project by Christian Rémillard, diver. The 3D model is licensed under CC BY 4.0: you may reuse it with credit. For a question, a correction or an archive photo of the lock: info@lock21.info.