Have Underwater Lights Brought Up To Code...

Blog by William N. Rowley Ph.D., PE and Donald H. Witte (deceased)

...When Replastering Existing Swimming Pools, Wading Pools, Spas, etc.

Over the last ten years, there have been a number of accidents involving electrical shock or electrocution in pools. These accidents have occurred due to electrical faults in the residence that found ground in a pool because an underwater light was not brought up to the National Electrical Code after the pool was re-plastered.  

The results of these accidents have been death or serious injury to those using the pool at the time of the fault.  This leads to family tragedies for innocent users of the pool and lawsuits that affect many parties at great cost. The good news is that these tragedies can be easily prevented by bringing the pool’s underwater lights up to code at the time of re-plaster or other remodeling tasks.

This type of accident usually occurs in older pools that were built before metallic niches were required by the code or on pools that do have a niche but the new plaster ring is not bonded to the installed metallic niche.  

The National Plasters Council and other influential organizations within the industry can help eliminate these accidents by raising awareness among their members about the dangers of failing to bring the pool up to code, and conversely how they can prevent tragic accidents and costly lawsuits by simply complying with the National Electrical Code. 

Electrical Hazard in Pools
Figure 1 shows an electrical hazard in a swimming pool.

Figure 1 shows a cavity in a swimming pool wall for an underwater light. This cavity in the swimming pool’s concrete wall is not compliant with the National Electrical Code in the following regards:

  1. The cavity has a metallic mounting ring at the edge (which is also an electrical hazard because it is neither bonded nor grounded), and
  2. The cavity has no grounded and bonded metallic niche in which the underwater light would be mounted.

Underwater lights and their niches (for swimming pools, wading pools, spas, etc.) need to be bonded and grounded in accordance with the National Electrical Code Article 680.

For the safety of bathers when an existing swimming pool is re-plastered, the plasterers should have a licensed electrical contractor inspect all underwater lights in accordance with the National Electrical Code Article 680 and to bring them up to code if it is determined that any aspect of the lighting system is not compliant. 

Underwater Light in PoolsFigure 2 shows a generic underwater light detail with typical notes for illustrative purposes.
When a plasterer resurfaces a swimming pool, he becomes a gatekeeper and in some situations the last possible line of defense against a possible electrocution event in the client’s swimming pool (or wading pool, spa, etc.).

That’s’ why when a plasterer has a pool’s underwater lights examined by a licensed electrical contractor during re-plastering, he is doing a great service to his client and could be preventing an electrocution event.

By doing so, he is protecting both his client and himself.


William N. Rowley, PhD, PE, CSP, is an invaluable resource in forensic engineering as an expert witness. World renown for his research, expertise, and innovations during more than 40 years of experience as a licensed professional engineer, he has received the industry's highest honors.

Dr. Rowley’s expertise in suction entrapment accidents, quadriplegic diving accidents, drownings and near-drownings, swimming pool design and construction, and swimming pool filter pneumatic separation ("explosion") is second to none. His knowledge extends to the environments of commercial pools, residential pools, and natural bodies of fresh and salt water. In both research and application he also offers expert analysis on construction accidents, in aquatic and non-aquatic environments, in the areas of slips and falls, dynamics, kinematics, and synergy of bodies in motion.

Facility Maintenance
Facility Maintenance
Underwater Lights
Pool Electrocutions
Electrical Shock from Pools
Re-plastering Existing Pools
Avoiding Pool Electrocutions