Paragraph 10
A person must not use a whistle within the estuary except—
(a)
as a signal of distress,
(b)
to prevent collision in compliance with the Collision Regulations, or
(c)
with the prior permission of the harbour master, for the purpose of—
(i)
the management of a race or any similar event,
(ii)
the training of a person in the use of a small vessel, or
(iii)
testing the whistle.