Drilling permits for offshore sampling shall be issued upon the payment of a fee of $50.00. No permit shall be valid for a period longer than one year. As a condition of issuance, each permittee shall agree to pay to the supervisor, to defray the cost of observers required by this resolution;

(1) For each necessary observer, the sum of $407.00 monthly in advance for each month or portion of the month during which drilling operations are to be conducted; and

(2) Such additional sum as equals the amount by which actual costs for observers exceed the sums paid in advance, said additional sums to be paid to the supervisor upon receipt of a statement therefor from the supervisor.