No vessel owner or operator shall—

(a) Signal a drawbridge to open if the vertical clearance is sufficient to allow the vessel, after all lowerable nonstructural vessel appurtenances that are not essential to navigation have been lowered, to safely pass under the drawbridge in the closed position; or

(b) Signal a drawbridge to open for any purpose other than to pass through the drawbridge opening.

[CGD 91-059, 59 FR 16563, Apr. 7, 1994]