Excerpts from the motor vehicle act, section 171. (Failure to signal would be a contravention of section 171 of the MVA) (How the numbers work).
Means of signalling
171 (1) Subject to subsection (2), if a signal is required a driver must give it by means of
(a) his or her hand and arm,
(b) a signal lamp of a type approved by the director, or
(c) a mechanical device of a type approved by the director.
(2) When a vehicle is constructed or loaded in a manner that makes a signal by hand and arm not visible both to its front and rear, or a body or load extends more than 60 cm to the left of the centre of the steering wheel, a driver must give signals as provided by paragraph (1) (a) or (b), and a person must not drive the motor vehicle on a highway unless it is so equipped.
So we can use hand signals instead of turn signals then right?