I never took a wreck diving course
exactly. My first wreck, besides mostly collapsed debris, was in Navy First Class Diving School where the week-long project was to raise a partially sunken small steel vessel in the Potomac River. The main deck was just above water but we had to patch a bunch of holes on the hull and inside compartments, pump her out, complete the obligatory cheering, re-sink her, and remove the patches for the next class.
All of the dives were surface-supplied so there wasnt much chance of getting lost. Unfortunately our class was in the middle of winter so we had to chop holes in the ice each morning. At least the wreck was cleaned so there wasnt fuel oil floating around like on a real newly sunken vessel.
There was more than a week of classroom time on salvage techniques before. I think that is where I became a brassoholic. I have no idea why because salvage is miserable and difficult work
but I did. My next wreck of any significance was the Andrea Doria a couple of years later. You see, baby steps arent necessary when you are a cocky hairy-chested Navy Deep Sea Diver and an invincible male in your 20s.
However, that training served us very well. The great majority of which can be summed up in one word: Research. The diving part isnt that complicated. Dont get lost in a black hole before you run out of gas
duh. Theres lots of ways to accomplish that and anyone that works is fine. Beyond that, research is what makes it interesting, safer, and gets the job done.
You can rarely locate detailed engineering plans, but you can study the heck out of everything you can find. That tedious process gives you time to reflect on most of the things than can go wrong and what you can do about it. In hindsight, that is the real payday of research.
Understanding ship construction is a huge part of that. Knowing which beams run port to starboard, how water-tight doors are made, how electrical cables are supported, and a myriad of other details can make the difference between getting lost and dead or sharing sea stories over beers later.