The invention describes a partially submerged ‘Detachable Island Rig’ (DIR) locked on a permanent ‘under-water basement’, to be instantly detached upon a rig-fire. The electrical wiring and metal tubing (with intervening rubber tubing) are cut and sealed, before the DIR disengages also from adjacent stationary rig. For stationing back onto the base, submerged despite changing tides, the buoyant forces of DIR are countered by a system of double pulleys within the basement, when also the DIR is aligned to be locked to the permanent base. The DIR has provisions for immediate functions of a conduction platform, living quarters, a basement entry, steering station, and uniquely designed life-boats and lift-boats. The ‘water-seal’ of the basement entry, not destroyed upon a rig-fire, serves as an ideal ‘fire-escape’ model, a safe refuge within the rig. A Continuation-in-part application extensively details water-sealed fire-escape devices of off-shore rigs, including a conventional jack-up rig.