Oh, this is where your fun starts!
You will probably get you wreck info from a mix of paper charts, chartplotter wreck marks, divers, commercial fishermen and books.
Much of what is on Imray charts for my local area is historical - many wrecks broken up so much they will barely be noticed on the fishfinder - and some wrecks simply recorded in the last position the ship was seen, often sinking miles away.
The positions for these wrecks will have been recorded in a number of ways - lat/long, Decca and Satellite derived positions. I have a note added to my Shipwrecks of the Forth book - SAT DERIVED POSITIONS MOVE GPS .12 min WESTWARD.
Now I get confused - do I add that on when going to the GPS or do I take it away.:blink:
Anyway, when you track down a few coordinates allow yourself a day to search the area. Pick a calm day with neap tides. Your first clue of being near a wreck may be just some blurry weed marks on your fishfinder. Do a block search around anything interesting and you may find your wreck.
My best wreck mark barely shows on the fishfinder - but it has fished cosistently for many years. One of the more obvious wrecks has never fished well.
Have fun!