If I'm reading this correctly, in NZ if you have a kayak overhanging your car by more than one meter, you must put a flag of regulation size on the end of kayaks during the day and lights at night. This is how they illustrate that.
This is from the Kiwi Association of Sea Kayakers website
Legislation The New Zealand Land Transport Safety Authority states: "Loads which overhang the outside of the body or deck of the vehicle by more than one metre to the front or rear, or more than 200mm to the left or right side need to carry special warning devices attached to the overhanging end(s)…/ vehicles may carry loads which are higher, longer or wider than the dimensions of the vehicle itself provided that the vehicle doesn't exceed the maximum permitted dimensions for that class and type of vehicle."
During the hours of daylight, there must be either:
* a clean white, or fluorescent red, orange or yellow flag, at least 400 mm long by 300 mm wide, or
* a frangible hazard warning panel, at least 400 mm long by 300 mm wide showing an orange diagonal stripe (200 mm wide) against a yellow green background, facing forwards or rearwards.
During the hours of darkness, the flags or hazard panels must be replaced with lights attached to the load as follows:
* for loads over one metre wide and extending more than one metre from the rear of the vehicle, one red lamp (facing toward the rear) on each side of load
* for loads up to one metre wide and extending more than one metre from the rear of the vehicle, one red lamp (facing toward the rear) at the centre of load
* for loads over one metre wide and extending from the front of the vehicle, one white or amber lamp (facing toward the front) on each side of load
* for loads up to one metre wide and extending more than one metre from the front of the vehicle, one white or amber lamp (facing toward the front) at the centre of load
* for loads extending more than 200 mm beyond the side of the body of the vehicle, one red lamp (facing toward the rear) on each side of the load at the rear and one white or amber lamp (facing toward the front) on each side of the load at the front.
These lights need to be clearly visible in clear weather at a distance of at least 200 metres during the hours of darkness. This applies to all vehicles, no matter when they were first registered.