North Sea Waves

The video below is of the Borgholm Dolphin. It is a 274 man accommodation unit in the North Sea. It is an spread moored semi-submersible. This is an Aker H3 design hull built in 1975. In heavy seas, it is customary to slack the anchor chains to prevent dragging and to pump out ballast, giving more "air gap" for waves to pass under the deck.