Thunder Bay National Marine Sanctuary
& Underwater Preserve

Thunder Bay National Marine Sanctuary, where is this place? Why is it special? What do they have there that would make a trip worthwhile?

In one short word History.

Thunder Bay National Marine Sanctuary and Underwater Preserve is located in the Great Lake Huron. Huron is about 220 miles long, 200 miles wide, and over 800’ deep. Huron is neither the largest, or the deepest of the Great Lakes but it has been the cross roads of Great Lakes traffic since the 1800’s. Whether the cargo was grain from Wisconsin or Illinois bound for the east, steel from Lake Erie ports headed for Chicago and points west, iron and copper ore headed from Lake Superior for the steel mills of Ohio and New York, it traveled across Lake Huron and rounded Thunder Bay Island.

On their way across Lake Huron vessel traffic had to make at least two major course changes, one off of Michigan’s Thumb and another between Thunder Bay’s “North Point” and Presque Isle to the north. Because the shortest distance between two points is a straight line, every mothers’ son of a Captain was trying to follow as straight of a line as he could in order to cut his travel time and increase his profit. This led to a lot of traffic passing quite close to the rocky shores of Thunder Bay Island and Presque Isle. The Thunder Bay Island Lighthouse was first commissioned in 1832. When traveling in fog with nothing but a watch and a compass to guide them navigation is known as "dead recogning." Any accurate measurement of speed disappeared with the land marks in the fog. There must have been many a sweaty palm as Captains decided when they have been on their current course long enough to be able to change course and avoid running aground on Thunder Bay Island or North Point. In both 1849 and 1850 the Life Saving Service reported on that Isalnd alone a side-wheel steamer was wrecked there each year in the fog. Add to these the many collsions and goundings and you have what makes Thunder Bay Special.

Not only did the Captains have to deal with their own ability to judge their ships speed to avoid running aground, they also had to watch out for other ships as well. In the hayday of the late 1800's upwards of 10,000 schooners, early steamers, and vessels of every other description were plying the waters of the Great Lakes. Estimates are that close to 200 shipwrecks still remain in this area of Lake Huron. Of these easily 100 have been proven to exist. The most recent is from 1966 with another couple from the 50’s but for the most part we are talking about 100 to 150 year old wooden shipwrecks.

To hover over the deck of a ship that sunk in 1854 and to think that news paper headlines of the day would have included the Charge of the Light Brigade in the Crimea, Abraham Lincoln’s first political speech, the announcement of the first oil refinery just built in Pennsylvania. And that people born before the Revolutionary War were still alive and may have even built this ship you are exploring. That is History, that is History brought to life and made real by a memory from the past lying on this Lakes bottom. To be able to touch the same wheel that the ships last mate held 100 plus years ago and to marvel of the men of iron who sailed these ships of wood, usually not much larger than a current day yacht. These experiences give the adventuresome diver a frame of reference not obtainable from a modern day replica. These shipwrecks will talk to those willing to listen.

The Great Lakes had a reputation of not having much more than 20' of visibility, well since the introduction of the Zebra Mussle in the 1980's that has changed. In the Spring 100+ viz is common from the surface down and 200' is not uncommon at depth. When placing the mooring buoys in May Sanctuary staff have reported being able to see 100' deep wrecks as soon as they entered the water. Later in the year algae populations soar and by September the top 100' of the water column has 30 or 40' of viz but dropping below the 120' level is like falling out of a cloud. Current and wind will change the exact depths but you can count on 50+ of viz at or below 130'.

Joseph Sobczak
Thunder Bay Scuba