The paper discusses issues of the impact of traffic density of the vessels on the sea surface to offshore underwater pipelines. The risk includes vessel foundering, sinking, grounding, dropping and dragging anchors, trawling fishing gear. The density of merchant, offshore field support vessels and fishing vessels presented by this paper is base for build risk model for underwater infrastructures. As an example it has been analyzed ships traffic over underwater gas pipeline between platform Baltic Beta and Wladyslawowo power plant.
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