What kind of wire do I need to run power to my dock?

Running power to a dock requires special waterproof wiring rated for wet and direct-burial applications — this is one of the most safety-critical electrical installations you can do, and it must be done to code.

Dock wiring is governed by specific rules in the Ontario Electrical Safety Code (OESC), and for good reason: electricity and water are a deadly combination. Electric Shock Drowning (ESD) is a real and serious hazard where AC current leaking into water can paralyze swimmers near an electrified dock. Getting this right isn't just about passing inspection — it's about keeping people alive.

Wire Types for Dock Installations

For the underground run from your home to the dock, you'll typically need direct-burial rated cable. In Ontario, this is commonly RWU90 (also called NMWU) — a moisture-resistant, direct-burial rated wire suitable for wet locations. It must be buried at the correct depth, typically a minimum of 600mm (24 inches) for direct burial, or shallower if run through conduit. Your licensed electrician will confirm the exact depth requirement based on your specific installation.

For any wiring on the dock itself — exposed to weather, splashing, and humidity — you need wire and fittings rated for wet locations. All outlets on a dock must be GFCI protected (Rule 26-700 of the OESC), and this is absolutely non-negotiable. A standard GFCI isn't always enough either; many dock installations require equipment leakage circuit interrupters (ELCIs) at the panel feeding the dock for whole-circuit protection.

What the Installation Involves

A proper dock electrical installation typically includes a dedicated circuit or subpanel, weatherproof outlet boxes and covers, marine-grade fixtures, and proper bonding of any metal components on the dock. The circuit size depends on what you're powering — lighting only might need a 15A circuit, while a dock with a boat lift, outlets, and lighting may need a 30A or 40A feed with a small subpanel.

An ESA permit is required for this work, and an inspector will visit to verify the installation. This is not optional — unpermitted dock wiring is a serious liability and insurance risk.

Ottawa-Specific Considerations

In the Ottawa area, dock installations on the Ottawa River, Rideau River, or area lakes also need to account for freeze-thaw cycles that can shift conduit and damage connections over winter. Your electrician should use conduit fittings and burial methods suited to our climate. Costs for a basic dock power installation in the Ottawa market typically run $1,500 – $3,500, depending on the distance from your panel, what you're powering, and whether a subpanel is needed.

This is not a DIY project. Beyond the permit requirement, the combination of water, electricity, and the ESD risk makes dock wiring one of the jobs where hiring a licensed electrician isn't just legally required — it's genuinely life-or-death. For a free estimate on your dock electrical project, reach out to Electrical Ottawa and we'll assess your specific setup.