Section 84 Exception for ship operated at speed necessary for safety
Transport Operations (Marine Safety) Regulation 2016
(1) A person does not commit an offence against section 81(2), 82(1) or 83(1) if—
(a) a ship must be operated at a control speed that is more than the highest speed at which the ship may be operated under the section (the statutory speed) because it is unsafe for the ship to be operated at a speed less than the ship’s control speed; and
(b) the person operates the ship at a speed more than the statutory speed only to the extent that it is reasonably necessary for the safe operation of the ship.
(2) In this section—
control speed, of a ship, means the minimum speed at which the ship can be kept on its course in the prevailing circumstances and conditions.