Welcome to the board. UK has so many wrecks it is unbelievable, of course they were not all treasure ships. Check out an earlier post I did on a wreck at
http://forum.treasurenet.com/index.php/topic,22019.0.html She was a real treasure ship and was partly salvaged by the locals in the early 1800'S. she is a virgin wreck as far a divers go, even though well known she has been left alone. You could start your research on this one and maybe eventually find her. She lies about 20 miles west of Swansea. Whatever there are not to many real ships which have as much possibility at the start of a venture.
If you do ever go there or in your research you find that there were also a few moidores found about 1 mile down the coast near Blue pool, its possibly a body drifted from the wreck to this locations as there were only a few coins. However I found a large anchor about ten feet from Blue pool itself many years ago. I did not have anything recover it nor had the time then, however I believe Robert Shefford who owns much of the land there, took a tractor at at later date and dug it out. If so it will be on his farm, which is actually a large caravan site. His house has huge history in the smuggling world.
This is just one wreck there are many, but do not get to well spread or you will just find out a few things about many ships and not a lot about one or two ships. If your research dries up then carfully file the information you have and move onto another ship. But when you continue researching sometimes you uncover things which make you open up old cases again, once you get bitten by the bug you are in for life so you make sure you file everything. (even things that do not seem important), have a complete file as best you can.
As for the physical part, get qualified, get fit, keep safe, take advice from experienced guys, this board is full of them who are willing to pass on information and help, there are many areas that some of the guys here are not just experts on paper but they have actually done it.
I hope your appetite is wetted, we do not see much activity on the board from UK and there is lots of stuff there.
Belgian Archaeologist Robert St?nuit, found The Girona's treasures after searching for while at Giants Causeway but he found the location after reading a local tourist guide it just said "Spanish rocks", he looked and found a gold chain almost immediately, and the rest is history.
Good Luck