Second World War wrecks lying in 20 to 45 metres off a coast that saw German, Soviet and Romanian shipping, preserved by cold…Second World War wrecks lying in 20 to 45 metres off a coast that saw German, Soviet and Romanian shipping, preserved by cold brackish water with no shipworm, and dived by a handful of Bulgarian technical teams. The Black Sea is the largest anoxic basin in the world, below roughly 150m there is no oxygen and therefore nothing that eats wood or flesh. That is why the deep Black Sea holds intact ancient ships, and why even its shallower modern wrecks corrode slowly. Anchorage: Varna is the largest port on the Bulgarian coast, with marinas and full shelter. Hazards: Depth in low visibility, and the Black Sea's oxygen-poor water means silt-outs clear slowly. Technical training required. Más