SUBMARINE CABLES, PIPELINES AND TUNNELS Mariners are reminded not to anchor, trawl or carry out any activities affecting the seabed in the vicinity of submarine cables, pipelines and tunnels. Mariners risk prosecution if they damage submarine cables, pipelines or tunnels. Submarine cables additional to those charted may exist. Submarine pipelines are not always buried, and their presence may significantly reduce the charted depth. Submarine pipelines may also span seabed undulations and cause fishing gear to become irrecoverably snagged, putting a vessel in severe danger. Gas from a damaged submarine pipeline could cause an explosion, loss of a vessel's buoyancy or other serious hazard. See The Mariner's Handbook.