The Fishing Vessels (Life-Saving Appliances) Regulations 1988

4.  Performance

4.1 A lifejacket light shall not be damaged in stowage throughout an air temperature range of −30 degsC to +65 degsC.

4.2 It shall operate as prescribed in paragraphs 4.7 and 4.8 throughout a sea water temperature range of −1 degsC to +30 degsC. It shall also be capable of operating in fresh water.

4.3 It shall be capable of operation in a sea-way when attached to a lifejacket .

4.4 It shall be visible over as great a segment of the upper hemisphere as is practicable when attached to a lifejacket.

4.5 A flashing light shall flash at a rate of not less than 50 flashes per minute and shall attain this rate within 5 minutes of activation.

4.6 A water activated light shall commence functioning within 2 minutes of immersion and have reached a luminous intensity of 0.75 candela within 5 minutes in salt water at temperatures of −1 degsC and +30 degsC, and within 10 minutes in fresh water at ambient temperature.

4.7 A fixed light and a flashing light with a flash duration of not less than 0.15 seconds shall have a luminous intensity of not less than 0.75 candela. A flashing light with a flash duration of less than 0.15 seconds shall have an effective luminous intensity of not less than 0.75 candela.

4.8 A light shall have a source of energy capable of providing the luminous intensity, or the effective luminous intensity, as appropriate, for a period of at least 8 hours.

4.9 The unit and the lifejacket attachment arrangements shall be capable of withstanding a jump into the water from a height of 4.5 metres without the unit being damaged or dislodged or causing injury to the wearer of the lifejacket.

4.10 The unit shall be capable of withstanding a drop of 2 metres onto a rigidly mounted steel plate or concrete surface.