Throughout the 1990s & until 2002 when I moved from Downtown Detroit [[Riverfront Towers) to California, I used to go SCUBA Diving along the shore in the Detroit River occasionally, either solo in the Riverfront Towers marina & in-front of the seawall, or with friends at various spots -- Belle Isle, in front of the Brodhead Armory [[before they put fencing up, to prevent us from doing it!), etc.

We did it mostly for the adventure -- trying to find 'treasure,' but for a few years, I was a Rescue Diver for the Spirit of Detroit 'Thunder Fest' hydroplane races and for a few days prior to that event, we'd all do training dives off a boat in the middle of the Detroit River, along the course [[familiarization with the current, visibility, bottom topology, etc.).

Visibility mostly depended on the when it last rained in the area. It was never great, but for the experienced diver, the 5'-15' average horizontal visibility [[assuming it was around Noon, with the sun directly overhead) was OK. The nice thing about the current is that if I stirred-up some silt when pulling some old bottle out of the bottom muck, the current would take it downstream, away from me if I held my place. We tried not to touch or stir-up the much much, because THAT is where the various nasty heavy metals, chemicals, etc. was.

Most of the best diving was within about 30' of shore, because that was around the maximum distance someone on shore would have tossed their old Coca-Cola, beer or milk bottle out to. Further out in the river, we'd find piles of mostly beer bottles in spots where fishermen had anchored their boats at, tossing their empties overboard and most of them drifting down-river a little but accumulating within a 5' radius of each other.

For the Thunderfest Rescue Diver training dives, it was mostly hard work -- they'd put a heavy object with some tags on it on the bottom [[usually no deeper than about 25') and a surface marker. The rescue boat would approach the surface marker from up-stream, and we'd enter the water from the moving boat at the position we thought appropriate, then when we thought it was the appropriate distance based on the current, we'd dive down to the target & retrieve the tag with our name on it. Sounds pretty straight-forward, BUT you couldn't see the bottom target or marker line at the time you needed to start descending, and if you didn't descend at the right time, by the time you got to the bottom, you would have overshot the target. With a little luck, you'd at-least see it as you passed it, then hit the bottom & try to kick hard against the current, going up-stream to get your tag off it and then surface triumphantly... But under the semi-legit guise of current & visibility familiarization, we'd also dive under parts of the MacArthur Bridge, which was obviously another good place to find stuff, albeit it was more likely to be 'contraband' than treasure. There was really just one reason someone would take a big knife or gun, or busted-open safe, etc. onto the MacArthur Bridge & toss it into the water...

It was really cool to be in the River, just 5 or 10 feet from shore, and come across some Coca-Cola bottle that dated back to the 1920s. I used to think that maybe my grandfather could have tossed it in, while walking along the riverfront on his first date with my grandmother... Oldest/rarest bottle I found dates back to the 1800s, but we found many plain milk bottles, medicine bottles and others that can't really be dated.

When I was doing the Thunderfest rescue Diver stuff, we were told that sometime in the early 1990s, a hydroplane had a blow-over & lost it's canopy, which was the same canopy used by F-16 fighter aircraft, and worth a lot of $$$. There was like a $10,000 reward at the time if we could find it. We never did. That sort of thing is heavy, BUT it's also something that could have continued to move pretty far down the Detroit River...

I don't find the news story about it on-line anymore, but when I was living at Riverfront Towers Apartments, apparently pretty much directly in-front of the complex but in about 85' depth in the middle of the shipping lane, there was a British warship that sunk sometime around the War of 1812. I fantasizing about putting on my drysuit & dual-120cfm air tanks & trying to find it, but I would have had to enter the river about half a mile upstream, ideally on the Canadian side, get down to the bottom ASAP and just hope that I drifted into it, then let the current keep taking me down the river as I worked to get back to the shoreline & out of the shipping channel before surfacing -- all pretty stupid to do. The safe & actually rather easy way to do it would have been for a boat to find it on a sonar or fish-finder, drop an anchored line to the upstream side of it, and then to drop down while holding onto the line for dear life, with a chase-boat ready to get me when I surfaced down-stream [[you can swim against the current but it takes a lot of strength & uses a lot of air, even if your using your hands on the sunken ship to help move up against the current).

Last I knew, SCUBA diving in the Detroit River --in the City of Detroit sections of it-- was illegal unless you got a permit from the DPD Harbormaster. We never bothered during our fun dives, but of course had official or unofficial consent & support from DPD Harbormaster, USCG, etc. for the Thunderfest stuff. On 'fun' dives, sometimes we would find a firearm. We'd complete our dives, get all our gear back into our cars, etc. and & then notify DPD of the find. None of them were happy about us finding evidence that they then had to deal with, especially if it looked like it'd been in the water for a while, but they never asked if we'd gotten the permit to dive in the river. In talking to a DPD friend in a position to know, they didn't like people diving/swimming in the river [[other than marked area like some spots on Belle Isle) because too many people couldn't swim to begin with, and/or didn't know how to deal with the current. Plus, the DPD Underwater Recovery Team had fun finding cool old stuff in the river & didn't want to share their treasure grounds with others.

We would wear full wetsuits, hoods & gloves, or even drysuits, and I'd often use a hand rake to poke around in the sediment. I was always concerned that sooner or later, I'd find a body or body-part, either seeing it in 'cement galoshes,' or worse -- something drifting into me & startling me, then me having a heart attack when I noticed it was a body. We'd take lots of fresh water & soap with us, and rinse ourselves off as best we could after we got out of the water, then really rinse our gear and immediately take showers when we got home, because we knew there were a lot of pollutants in the Detroit River [[& for that reason, I call it the Detroit River, not "water"). One gross thing we'd see dozens of all the time floating past us during a dive -- plastic tampon applicators. After a couple dives, I'd develop a rash...

Diving the Riverfront Towers Apartments Marina was great because the seawall blocked the current. I'd tow a surface marker above me, and my friends lounging on their boats would warn any of the boaters that may actually leave the marina [[99% of the time, the tenants that had boats there never took them out!). In addition to the beer cans & bottles, I'd find cellphones, some watches, keys, and other things that people would accidentally lose overboard. One boat-owning neighbor pointed to the exact spot his "$10,000 gold & diamond ring" fell off his finger & into the river at the marina. I knew it was only about 10' deep there, and also knew that a heavy ring should pretty much have dropped straight down, so I figured I'd be quite the hero when I found it & that I'd get to part on his 41' Sea Ray whenever I wanted to. I spent about an hour feeling around in the muck, which was about 2' deep It was like sticking your arm into chocolate pudding) but I never found it! He's probably still thinking I found it, but just didn't tell him....

Coldest dive I ever made was New Years Day in I think 1999. It was 28 degrees at a depth of 10' off of Belle Isle. At 28 degrees you'd expect it to be frozen, but due to the current --and probably all the chemicals in the River-- it wasn't.

For Ray1936: I live in Henderson NV now. Lake Mead has lots of underwater history to it -- remember, it was dry land, with some communities: https://www.youtube.com/watch?v=M1RTCp3dcIo
trees, etc. before it was deliberately flooded to become a water reservoir with the construction of the Hoover Dam. There's a very special B-29 bomber aircraft in it:
https://www.nps.gov/lake/learn/histo...-mead-b-29.htm Plus the popular swimming & cliff jumping spots will have jewelry, wallets, watches, etc.