When your out on a boat in the open sea then you will want to have a power inverter for some extra power to your devices. If you decide for example that you want to have a romantic candle light vigil for your sweetie out in the middle of the ocean then you will want to get a high powered inverter to power some extra devices you may find yourself needing like speakers, special lighting and things of that nature. Power inverters are built into alot of boats already but their are times that you will need alittle more power.