Diving in Ontario
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Great Lakes Wreckdiving
Ontario Shore Dives
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What's so great about diving in Ontario?

The things that best distinguish Ontario diving from diving in other parts of the world are:
  • it's fresh water,
  • it's #@*% cold, and
  • there are a lot of very well-preserved shipwrecks, as a result of those other two factors.

Under cold, freshwater conditions, the rusting and marine life growth that eventually claim shipwrecks aren't present to anywhere near the same extent. The amount of underwater life in Ontario's lakes and rivers is minimal compared to any halfway-respectable tropical reef. Also, the salt that speeds corrosion isn't here.

In the ocean, wrecks from as recently as World War II experience significant deterioration, while wooden ships wrecked in Ontario's lakes in the 1800's are in better shape.


It's been said that there are only two water temperatures in Ontario: hard, and soft. For a few months each year, you can walk on the stuff.

Water reaches its greatest density at 4 degrees Celsius (39 Fahrenheit). As a rule of thumb, that's the temperature you'll find below about 50 feet, give or take a bit, depth year-around in the Great Lakes and most larger, deeper bodies of water. Especially toward late summer, though, the surface layer will be warmer and there'll be a decent thermocline somewhere between 20 and 60 feet. Near-surface temperatures of 21C (70F) have been observed in the east end of Lake Ontario, in Lake Erie, and in other shallower bodies of water. Lake Superior and Lake Huron don't get as warm, but I've been assured (by somebody who would know) that a temperature of 66F was observed one September day at the 30' deco stop over the last resting place of the Edmund Fitzgerald.

What does this mean for the diver? Well, a full quarter-inch wetsuit with hood, gloves, and boots is the basic attire. No shorty suits or thin ones here! Drysuits are very popular, and most "serious" divers, especially the ones who don't want to stop diving just because it isn't summer anymore, will have one.

The optional anti-freeze kits available for most regulators are also highly recommended. These provide a layer of non-freezeable oil around the regulator's working parts (the piston or diaphragm) and prevent ice from forming and blocking the works. The usual consequence of that happening would be a free-flow, in which all your air comes out at you over the course of a few short minutes. This tends to end dives fairly quickly.

Fresh Water

Every now and again a saltwater diver in rec.scuba will mention rinsing off their gear after a dive, and I'll remember that you need to do that when diving in salt water. Climb out of Lake Huron, though, and you've already rinsed yourself off in clean, fresh water. You can even sneak a drink of the stuff if you get thirsty during your dive.

As a rule of thumb, I consider the lakes clean north of the Sarnia-Detroit stretch, and take precautions (BuroSol(tm) in the ears, and try not to drink the stuff) further downstream.

The Wrecks

The Great Lakes and their associated rivers were, and still are, the major transportation route into a significant part of North America. The Lakes have a reputation for violent storms, and with their smaller size can whip up into a fury much more quickly than the oceans. Because of the restrictions on the sizes of vessels that could negotiate some of the rivers, waterways, and locks, especially earlier this century, many of the vessels were smaller than seagoing vessels. As a result of all this, the Lakes are littered with shipwrecks.

Many wooden vessels from a century ago are still in reasonable shape. Much depends on the depth of the wreck; shallower ones have been battered by storms and torn by winter ice. Some newer steel vessels have also come to grief, so there's a fair bit of variety. Almost every wreck has something that makes it unique. No two wrecks are quite the same.


Last modified 2004-11-17 by Anthony DeBoer.