Tidelands Limited IV, Houston, has applied for a Title XI guarantee to aid in financing the construction of a jackup drilling rig. The proposed builder, Bethlehem Steel Corporation's Sparrows Point, Md., yard, expects to complete the vessel in April 1982. The drilling barge will be used to drill for oil and gas in water up to 200 feet deep.

If approved, the guarantee will cover $24.5 million, or 75 percent of the vessel's $30.6-million estimated cost.