29 CFR §1915.85

1. (a)The employer shall service each vessel's radar and communication systems in accordance with 29 CFR 1915.89, Control of Hazardous Energy.
2. (b)The employer shall secure each vessel's radar and communication system so it is incapable of energizing or emitting radiation before any employee begins work:
   1. (1)On or in the vicinity of the system;
   2. (2)On or in the vicinity of a system equipped with a dummy load; or
   3. (3)Aloft, such as on a mast or king post.
3. (c)When a vessel's radar or communication system is operated, serviced, repaired, or tested, the employer shall ensure that:
   1. (1)There is no other work in progress aloft; and
   2. (2)No employee is closer to the system's antenna or transmitter than the manufacturer's specified safe minimum distance for the type, model, and power of the equipment.
4. (d)The employer shall ensure that no employee enters an area designated as hazardous by manufacturers' specifications while a radar or communication system is capable of emitting radiation.
5. (e)The requirements of this section do not apply when a radar or communication system is incapable of emitting radiation at levels that could injure workers in the vicinity of the system, or if the radar or communication system is incapable of energizing in a manner than could injure workers working on or in the vicinity of the system.