assuming an ice defensive hull in water configuration as shown in fig3 in fig3 ice tends to dampen waves and d rough seas so the sea surface 12 appears less threatening however the hazards of the marine environment have only altered and not lessened when the ice worthy jack up rig 10 assumes its ice defensive hull in water configuration the hull 20 is lowered into the water to contact same but not to the extent that the hull 20 would begin to float a significant portion of the weight of the rig 10 preferably remains on the legs 25 to hold the position of the rig 10 on the drill site against any pressure an ice flow might bring the rig 10 is lowered so that inwardly sloped ice bending surface 41 bridges the sea surface 12 or ice water interface to engage any floating ice that may come upon the rig 10 the sloped ice bending surface 41 runs from shoulder 42 which is at the edge of the deck 26 down to neckline 44 ice deflector 45 extends downward from neckline 44 thus when an ice floe such as shown at 51 comes to the rig 10 the ice bending.