A mobile, year-round drilling system (MYADS) for drilling offshore wells and/or performing other offshore activities at multiple, successive locations in an arctic or sub-arctic environment is provided. The present invention combines the ability to move to different locations and the strength to resist ice loading when on location and when ice-covering is present in the arctic or sub-arctic environment. The MYADS applies a multiple leg “jack-up” concept in which supporting legs are lowered through a hull to touch down on the seabed and elevate the hull out of the water.