Pleasure craft 12 m (39’4”) or greater in length must have a fitted whistle. Check the Collision Regulations for the technical criteria the whistle must meet.
Pleasure craft less than 12 m (39’4”) in length need a sound-signalling device if they are not fitted with a sound-signalling appliance. The sound-signalling device can be a pealess whistle, compressed gas horn or an electric horn.
Vessels less than 20 m (65’7”) in length or that are constructed primarily of non-metallic materials must have radar reflectors, unless they are not essential to the safety of the vessel, or the small size of the vessel or its operation away from radar navigation makes compliance impractical. If properly positioned, they help larger, less manoeuvrable vessels detect your presence on their radar screens. They should be located above all superstructures and at least 4 m (13’1”) above the water (if possible).