The lessee shall be diligent in the exploration or development of the geothermal resources on the leased lands. Failure to perform diligent operations may subject the lease to termination by the board. Diligent operations mean exploratory or development operations on the leased lands, including without limitation geochemical surveys, heat flow measurements, core drilling, or drilling of a well for discovery, evaluation, or production of geothermal resources.
Haw. Code R. § 13-183-61