Daymarks

Daymarks are shown by day in all weathers on boats to denote certain activities in which they are engaged.

In restricted visibility the appropriate lights may also be displayed by day. You must be able to recognise these daymarks.

Vessel restricted in ability to manoeuvre

Black ball, black diamond and black ball (e.g., boats engaged in: Flying aircraft, cable laying, replenishment at sea, underwater operation, servicing navigation marks, towing, where manoeuvre is restricted by tow).

This signal does NOT indicate distress or a need for help. (When at anchor, vessel also shows anchor shape).

Vessel at anchor

(not required for boats of less than 7m). When at anchor not in a channel or channel approach, or a usual anchorage, etc. Forward, where best seen one black ball.
Vessel under power with sails set (motor-sailing)

Forward, where best seen one black cone, point down

Power-driven vessel towing

Vessel being towed if length of tow exceeds 200m. On each vessel where best seen one black diamond

Vessel aground

This signal does NOT indicate distress or a need for help. (Not required for boats under 12m length.) Where best seen three black balls.

Vessel not under command

(Not required for boats under 12m.) NOT distress, but indicates inability to manoeuvre. Two black balls.

Boats fishing

Trawls, nets or other gear (underway or at anchor) two black cones, point inwards OR, if fishing vessel is under 20m length, she may instead show a basket.

Vessel constrained by her draught

(power-driven vessel restricted to a narrow channel by her draught and thus unable to deviate from course). Where best seen one cylinder.