Will the shore power suit your yacht?

Reading the supply specification

Voltage describes the electrical potential of the supply; frequency, expressed in hertz or Hz, describes the rate of its alternating cycle. Phase describes the supply arrangement, commonly single-phase or three-phase. Current, expressed in amperes or amps, is another limit. A statement such as “100 amps available” is incomplete without the voltage, phase and connection arrangement.

These details matter independently. A connector that physically fits does not establish that the supply suits the yacht’s equipment. Equally, matching voltage does not establish matching frequency. The chief engineer or electro-technical officer needs the berth’s actual specification and the yacht’s approved receiving arrangement before confirming compatibility.

Separate adaptation, isolation and conversion

A plug adaptor changes the physical connection; it does not by itself convert voltage or frequency. An isolation transformer provides electrical separation and may change voltage according to its design. A frequency converter performs a different job, conditioning the incoming supply to the output that the installed system supports.

The distinction is visible in manufacturers’ documentation. Victron’s isolation-transformer guidance lists voltage configurations and 50/60 Hz operation. Atlas’s shore-power converter specifications separately describe accepted inputs, output and power ratings. Those examples explain the categories; neither establishes the capability of equipment installed on your yacht.

Give the marina the receiving system’s accepted input, rather than only the electrical standard used inside the vessel. A yacht with conversion equipment may accept a supply different from its onboard output, but only within the installed equipment’s limits. Do not infer that a converter makes every berth usable.

Match the supply to the planned load

Electrical load is the demand from the equipment running aboard. The practical question is whether the accepted connection can support the operations planned together, including temporary work or unusually heavy use of hotel services. A lightly occupied yacht and a full guest complement may have different alongside requirements.

Converters and supply equipment may be rated in kilovolt-amperes, or kVA, while equipment demand may be described in kilowatts, or kW. These describe apparent and real power respectively and are not automatically interchangeable. Leave the capacity assessment to the engineer using the actual system information, rather than comparing two numbers with different units.

If the available supply requires some loads to be staggered, establish what that means for the visit. It may be workable for maintenance but inconvenient during a guest turnaround. This is a berth-selection consequence, not merely an electrical detail to resolve after arrival.

Confirming the allocated berth’s supply

As a local example, IGY’s Yacht Club Isle de Sol specifications list several power configurations, including a 480 V, 100 A three-phase option. A marina-wide list does not identify which connection will be assigned to your yacht. Obtain the specific berth, supply details and connection arrangements together.

Include cable reach, the route between pedestal and inlet, and who will attend the connection. IGY’s own marina rules ask guests to have a dock attendant turn on and meter utilities. Arrange connection and testing by competent personnel under the receiving facility’s rules and the yacht’s electrical procedures.

Make power part of the berth decision

Build a Sea Grapes berth brief with the engineer’s receiving specification, expected demand and essential alongside operations. If compatible power is essential to the call, say so at the start of the enquiry. If an alternative operating plan is acceptable, describe it without assuming generator use or temporary equipment will be permitted.

The Great Bay and lagoon comparison puts that electrical requirement alongside access, work and departure timing. A berth becomes a useful option when all of those requirements can be met together.