Although leaked chemical warfare (CW) gases rapidly hydrolyse in sea water, potential risks of serious contamination will exist for many decades for sailors, fishermen and coastal visitors of the Baltic Sea and Skagerak, in particular concerning contact with lumps of mustard gas. Blue prints of emergency plans should be available in order to confine, bury or destroy ammunition at risk. For that reason bottom current maps should be available to predict the transport of lumps over the sea bottom. Test should be made in hydraulic laboratories about the correlation water current and lump transport. Modelling may predict the hotspots in the future. This is an updated document.