Meaning of jack-up rig

jack'-up rig"

Pronunciation: [key]
  1. an offshore drill rig or platform having a floating hull fitted with retractable legs that can be lowered to the seabed to elevate the hull above wave level. Cf. semisubmersible.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.