Boats run on DC circuits, but all of our land based creations require AC power. When deciding to go cruising, you need to ask yourself: Do I need AC power?
There are two main ways of producing AC power when not connected to shore power. Option 1 is to crank up your generator and enjoy AC power for as long as your fuel reserves can support.
Option 2 is to crank up your inverter and switch your DC power into AC power.
Option 1 will provide you with a lot more power compared to Option 2, but it requires that your boat already has a generator. If you don't you could be looking at several thousands of dollars to get your boat ready for Option 1.
Inverters are much cheaper, and far easier to install when compared to generators. Their price greatly depends on how much power you will need from it at any moment. If you just need to charge your phone, or run your laptop, those inverters are very inexpensive. If you want to power your hair dryer and water heater, then you better be prepared to shell out a lot more money.
While inverters can theoretically provide you as many watts as you would need, they can't do it forever. Their secret relies on inverting your 12V DC power into 110V AC. In other words, they are drawing on your batteries a lot! The more watts you get out of your inverter, the more amps it's sucking out of your batteries.
The easiest solution is to do without any creations that use AC power and only use electronics that run on DC power. A laptop may require an AC plug, but most tablets can be charged via USB port which can be fed by your battery system.
When setting off to go cruise, Maddie and I discussed the dilemma and we opted to go without. We switched from laptops to iPads, which allowed us to go without the power supply issue. Maddie cut her hair short, so she no longer needs a hair dryer; and we heat our shower water with the sun so we don't need to run the water heater.
All in all, as it stands, we are planning to go cruising without an inverter.
The beauty of cruising is there will always be a new port along the way. If we find that we really do need an inverter, though I don't know why at the moment, then we would stop and put one in. Until then, we will have one less electronic device to worry about as we go cruising with the money we would have spent on the inverter still in our pocket!