Launching an offshore platform jacket - GIF

[Frank S]

perhaps some context..... what is an "offshore platform jacket"?

I would assume some kinda base for an offshore oil rig/living community/scientific station/airport?

Does it get anchored to the sea floor?
Does it span sea floor to surface or do they get "stacked"?

Most of the offshore drilling operations consisted of the drilling platforms sitting on top of what is called a jacket. these can be quite large and too long to be fully fabricated in one piece in the yards so multiple sections will be constructed side by side then launched into the sea then connected together. Judging by the shear number of waterproof lighting fixtures mounted on this one it is safe to say this would be the section which will be mounted at or just above sea level then the platform will be added to the top of it. The platforms are huge as you can imagine since they house the crews and can have several drilling operations going on at the same time to make the cost of building such a rig worthwhile