Subpart 161.013_Electric Distress Light for Boats
Sec. 161.013-9 Independent power source.
(a) Each independent power source must be capable of powering the
light so that it meets the requirements of Sec. 161.013-3(a)(1) and
emits a recognizable flash characteristic of the International Morse
Code for S-O-S at a rate of between 3 and 5 times per minute after six
hours of continuous display of the signal.
(b) If the independent power source is rechargeable, it must have a
waterproof recharger designed for marine use.
(c) If the independent power source requires external water to form
an electrolyte, it must operate in sea water and fresh water.