Did you know that a thermonuclear bomb was ditched off the Georgia coast in 1958 and has yet to be recovered?

So I happened to be watching TV last night and a program about this came on the Science Channel. You can read about it here. According to the paperwork signed by the pilot before the mission started, the plutonium-containing capsule required to arm the bomb was not inserted into the weapon. However, it does contain a significant amount of enriched uranium in the secondary (as well as deuterium/lithium fussion fuel and 400 lbs. of high explosives). The water is shallow but extremely murky. The sediment is deep and is naturally radioactive. These factors have foiled all searches made to date.