Underwater Treasure Search: German Subs, AKA U-Boats, & Treasure-Hunting and U-Boats

German Subs, AKA U-Boats
In World War 2, the U-Boats were the German's deadly ninjas of the sea... silent, deadly, and often unseen. The Allies figured out their secrets, however, and start wiping these subs out in 1945. One way they did this was with Mine Alley, an area between Ireland and Britain that was basically littered with mines chained to boxes on the seabed. There was a narrow area where surface boats could pass through safely, but underwater subs were in extreme danger. Another was the tin-opener technique, where a ton of depth-charges were tossed into the water from either boat or plane... or even both! These charges exploded at a certain depth, and could tear subs apart!
Of course, this wasn't the only danger U-Boats had. Even before 1945, U-Boats had one big enemy... sea pressure! An U-Boat was basically one big complex pipe and valve system, along with some other stuff. If one seal blew off, or something in that complex system went off, the pressure attacked, the sub broke, and then it sank. And there wasn't any rescue from a sunken sub!

Treasure-Hunting and U-Boats
Treasure isn't just gold, silver, or low-alpha lead... knowledge is a valuable treasure too! This is why some folks go chasing after the wrecks of U-Boats. There are many mysteries there! And many untold and unknown stories to be found...
However, there can be trouble! Other than the constant fishing nets, currents, tides, and weather, some areas, like Mine Alley, can be littered with Ally mines! These can blow up your R.O.V., and then the shock-waves can zip on up and badly damage your boat! So when hunting in Mine Alley, watch yourself... some mines have stuck around, and are waiting for prey! And, sometimes, there aren't many clues in sight.
There are good things to checking out U-Boats, however. There can be a ton of clues to which U-Boat it is you're checking out. Before 1945, U-Boats had deck-guns. Production of subs with these stopped, and older boats that still had them got them removed, though they had a gun-mold still on deck. So if you find a gun-mold, you can figure it was pre-1945.
Also, U-Boats not only had periscopes (like any submarine you can think of), but also snorkels! These snorkels got oxygen to the engine, so the sub could stay down longer. How they're good today is that the periscopes and snorkels were adjusted and upgraded constantly, so the type of periscope and snorkel an U-Boat has can help narrow down which U-Boat you're looking at! And there were other upgrades and features (like life-raft containers on or near the sub) that help pinpoint which U-Boat the wreck is.