A mix of liftboats and jack up rigs.
A liftboat is a self-propelled, self-elevating vessel with a relatively large open deck capable of carrying equipment and supplies in support of various offshore mineral
exploration and production or offshore construction activities. A liftboat also has the capability of rapidly raising its hull clear of the water on its own LEGS,
so as to provide a stable platform from which drilling, maintenance or construction work may be conducted.