DanBi Marine

Shore Power

Proper Ground Fault Protection is critical for the safety of people when on or around marinas and docks.  The risk of Electric Shock Drowning (ESD) and electrocution is very real, and government regulatory requirements are in place to reduce these risks.  In efforts to make marinas and docks safer, the 2020 version of the National Electric Code (NEC) requires ground fault protection on the wiring (feeders, branch circuits, etc.) installed on the docking facility, not just at the receptacles.  With this new change in the NEC, the vast majority of marinas and docks are out of compliance and subject users to substantial risks. DanBi Marine has the experience and systems that can meet the regulatory requirements stated in the 2020 NEC and reduce your risk as a user, boat owner, marina owner, employee, and insurer.

Why is Electrical Shock Drowning Dangerous?

Electric Shock Drowning (ESD)

According to the Electric Shock Downing Prevention Association, “Electric Shock Drowning (ESD) is the result of the passage of a typically low-level AC current through the body with sufficient force to cause skeletal muscular paralysis, rendering the victim unable to help himself / herself, while immersed in fresh water, eventually resulting in drowning of the victim.  Higher levels of AC current in the water will also result in electrocution.  Electric Shock Drowning (ESD) has become the catch all phrase that encompasses all in-water shock casualties and fatalities.”


When AC current is present in the water at a higher level than what would cause ESD, the swimmer will be subject to electrocution followed by drowning.  Furthermore, anyone who enters the water in attempt to save the victim will also be subjected to electrocution.

How Does Water Become Electrified?

If there is an electrical failure on a boat or electrical equipment (i.e. panel), and it is in contact with the water, the electrical current from the boat or the equipment will leak into the water.  The amount of current present in the water will depend on the severity of the electrical failure and the shore power wiring.

Is It Possible to Test the Water?

Testing the electrical system, ground fault protection and stray current in the water at marinas should be completed annually (minimum requirement per 2021 NFPA 303 5.20).  DanBi Marine has the testing equipment and experience to conduct these test at least annually.  Testing of all these components helps to ensure the marina is as safe as possible as all these components need to be working together to keep people safe.

 For more information review these regulatory requirements:

 National Electric Code (NEC) 2020

555.35 A(3) Feeder and Branch-Circuit Conductors with GFPE

Feeder and branch-circuit conductors that are installed on docking facilities shall be provided with GFPE set to open at currents not exceeding 100 milliamperes. Coordination with downstream GFPE shall be permitted at the feeder overcurrent protective device.

555.35 A(1) Receptacles Providing Shore Power

Receptacles installed in accordance with 555.33(A) shall have individual GFPE set to open at currents not exceeding 30 milliamperes.

555.2 Definitions

Docking Facility.  A covered or open, fixed or floating structure that provides access to the water and to which boats are secured.

Call DanBi Marine today to set up a free onsite consultation!