Boats require a reliable and well-maintained electrical system to operate safely and efficiently. The size and complexity of these systems depend on the type of boat and its intended use. Below are some of the key electrical components and requirements found on most boats:

1. **Power Generation**
– **Battery Systems**: Most boats rely on batteries to power their electrical systems. Marine batteries are designed for deep cycling, meaning they can discharge and recharge multiple times without degrading quickly.
– **Alternators**: Boats with engines use alternators to charge their batteries while the engine is running.
– **Solar Panels**: Some boats, particularly sailboats and long-range cruisers, may use solar panels as an auxiliary power source, particularly for maintaining batteries when the boat is at anchor or away from shore power.
– **Wind Generators**: Used on some sailing boats for supplementary charging of batteries, especially on long voyages.

2. **Shore Power**
– **AC Electrical System**: Many larger boats are equipped with shore power systems that allow them to plug into AC power at marinas. These systems typically run at 240V in Australia and power appliances, battery chargers, and other AC-reliant systems.
– **Power Inverters**: Inverters convert the boat’s 12V or 24V DC battery power to 240V AC power to run appliances like microwaves, air conditioning units, and laptops when shore power is unavailable.

3. **Lighting Systems**
– **Navigation Lights**: Essential for safe boating, navigation lights help other vessels identify the type and direction of your boat. These lights must meet specific legal requirements.
– **Interior and Deck Lights**: Boats are fitted with a range of lighting solutions for cabins, cockpits, and decks, often using energy-efficient LED systems to minimize battery usage.

4. **Communication and Navigation Equipment**
– **VHF Radios**: Used for communication with other vessels, marinas, and rescue services. VHF radios are crucial for safety, especially in offshore waters.
– **GPS and Radar Systems**: Electrical navigation equipment like GPS chartplotters and radar systems are standard on most boats, providing essential data for safe navigation.
– **Autopilot**: Many larger vessels are equipped with autopilot systems, which require a reliable electrical power supply.

5. **Entertainment and Appliances**
– **Stereo Systems**: Marine-grade stereo systems for entertainment while at sea or anchored.
– **Refrigerators and Freezers**: Particularly on liveaboard boats, refrigeration systems are often a high energy consumer that requires careful electrical planning.
– **Air Conditioning Units**: Larger boats, especially in tropical Australian waters, may have air conditioning systems that rely on AC power either from shore or a generator.

6. **Bilge Pumps and Safety Systems**
– **Bilge Pumps**: Electrically powered bilge pumps are essential for keeping water out of the hull and are usually connected to automatic float switches.
– **Fire Detection and Suppression Systems**: Some boats are equipped with electrical fire detection systems or electrically controlled fire suppression systems.

7. **Battery Management and Monitoring Systems**
– **Battery Monitors**: These systems track battery levels and alert boaters when batteries are low, helping to prevent failures.
– **Charge Controllers**: For boats using renewable energy sources like solar panels, charge controllers regulate the power coming into the batteries to prevent overcharging.