Why shore power needs extra care
A boat sits in conductive salt water, gets bumped, flexes and corrodes. Every one of those things is hard on electrical connections. Australian Standards treat marinas and boats separately for this reason: AS/NZS 3004.1 covers the marina supply and AS/NZS 3004.2 covers wiring on the boat.
Never ignore a tingle
A tingle from a rail, ladder or the water near your boat means current is going somewhere it should not. Faults on a boat, or neutral-to-earth voltage carried from the shore supply, can put voltage on metalwork and into the water around it. A small current in water can cause muscles to lock up, which is why electric shock near marinas can lead to drowning. If you feel a tingle, unplug the shore power lead at the pedestal, keep people out of the water and get the boat checked before plugging back in.
Your shore power lead
Each marina sets its own rules, so read yours. As an example of what Queensland marinas expect, one major marina's 2026–27 policy requires:
- One heavy-duty, three-core lead in one continuous length, rated to match the outlet
- No household extension leads, double adaptors or power boards
- A current test and tag, renewed every 12 months
- Leads kept out of the water, not wrapped around cleats or pedestals, and removed when not in use
- Monthly checks by the owner of the lead, plugs and the safety switch on the lead
Why shore power trips
- Water or corrosion in the inlet, plug or socket
- A failing appliance on board: hot water service, battery charger, air conditioner
- Damaged wiring behind panels or in the bilge
- Too much running at once for the outlet's rating
- A damaged or wet lead
Most of the time the lead tests fine and the fault is on the boat. That is why the boat's wiring, not just the lead, needs testing.
Corrosion and the shore earth
Plugging into shore power connects your boat's earth to every other boat on the marina. That can speed up galvanic corrosion of underwater metal. A galvanic isolator in the earth line can help, and anodes need regular checking. If your anodes are wasting away fast, ask us to look at it.
Imported boats
Boats built for overseas markets can have 110 V outlets and appliances. Those need to be isolated or converted properly, and clearly labelled, so nobody plugs the wrong thing in.
From our job sheets
Marine work is a big part of what we do, mostly at Scarborough and Newport marinas, with regular jobs at Redcliffe, Manly and the Gold Coast. Recent shore power jobs include fault finding a complete loss of 240 V shore supply to a vessel at Redcliffe, a boat that kept tripping shore power where the lead tested fine and the fault was on board, isolator replacements, and 110 V outlets on an imported boat isolated, terminated and labelled.
What it costs with us
Marine fault finding is quoted per job. Most boat work is done at our Clontarf workshop, and for bigger jobs we work on board at your berth (call-out surcharges apply). See our marine electrical services and Scarborough and Newport marina work.