This is an old plastic model kit of the North Sea 10,000 ton Oil Rig 'Sea Quest' that I bought off eBay. The scale is listed as 1" = 70 ft, which I figure is pretty darn close to 1/700. The measurements on the model are 5 1/2" x 5 1/2" x 5"
I'm not sure of the manufacturer, however judging from the yellowed instructions I would guess it was produced in the 1970's. The kit was sold in a plastic bag. It is advertised as an "easy no-glue assembly," which is far from the truth. The parts did not fit well, and required much cutting, sanding (and glue) to get them together.
The kit came with a small set of British Petroleum (BP) decals to make the rig as it appeared when it was first built. I decided to make my own decals for the China National Offshore Oil Corporation (CNOOC).
On the helipad is a custom-made S61N "streched" Sea King. This version first flew on August 7, 1962 and retained the floats for overwater operations as it was designed for oil rig support duties. The S61N was upgraded to the MkII standard with improvements including more powerful CT58110 engines giving better hot and high performance, vibration damping, radar, and other refinements.
There is a paragraph at the bottom of the instruction sheet stating: "The Sea Quest is semi-submersible, and has drilled in 230 feet of water. In these conditions it is floating off the sea bed, being kept in position by nine 30,000 lb. Danforth anchors."
Despite the difficulty in building this model, it has a good amount of detail. I love its uniqueness and wish there were more kits like this available on the market.