Modular structure for protecting an offshore vessel in a body of water from forces of ice features comprising a protective harbor wall, a flotation support, a pile, and a telescoping connection. The telescoping connection is operatively coupled to the protective harbor wall and the flotation support and constructed and arranged to axially move the protective harbor wall between a retracted position and a raised position. The protective harbor wall is constructed and arranged to enclose a harbor space and to counteract the forces of ice features. The flotation support supports the protective harbor wall and is constructed and arranged to change net buoyancy of the modular protective structure to submerge the structure such that the flotation support is positioned on a seabed. The pile is constructed and arranged to be partially disposed in the seabed to maintain the position of the flotation support on the seabed.