Wreck lists are sent from this end by e-mail attachment, larger files will be zipped. If you are not sure which report you want then e-mail. If it is just one or two vessels you wish to ask about or where a relative was lost then e-mail and a search will made to see what can be found (gratis). No database has a list of "all" vessels wrecked or sunk. They have a list of what they have been able to accumulate to this point in time.
The best place for a detailed cargo list is probably Lloyds of London. Hull and cargo are both insured separately. If paid out, the “Insurer” owns ship and cargo. If you are going after the cargo make sure you have a deal with the “owner”. If you buy and old wreck, be careful, you might find yourself liable for future problems relating to that wreck..
For those of you who are into maps showing wreck locations may I suggest Google Earth, and it’s free to download. There are indeed several wrecked ships to be seen worldwide and there are places that you can actually search underwater. It also shows the long’ and lat’ that you have the pointer sitting at. Learn to create overlays showing the data that you wish to save, then, why stop at just one overlay. Quite the program, indeed.