One option is to pack up laundry, toss it into the dinghy, and motor to shore in search of a laundromat. While this would be workable, laundromats can get rather expensive. And the expense isn't just the $3+/load, it is also the amount of time taken to babysit machines at the local laundromat. Undoubtedly, we will have to do this for some things like big, bulky, bedding items. But for normal day-to-day laundry, I'd really like another option.
Some nicer boats have washing machines installed. These are often interesting devices that include both a washer and dryer in a single unit. Unfortunately, these units can consume a fair amount of water (10 to 20 gal/load or so) as well as electricity (most are 110 volt units running 10~15 amps). Even if we could justify the water and power usage, we don't really have space for one of these units unless we converted one of the berths to a laundry room as they are about the size of an apartment washing machine. Not really an option.
Taking another step down, there are small, portable washing machines. These can range from something about 2/3 the size of a small apartment washing machine down to an appliance not much larger than a food processor or large blender. The size and weight not only determine the amount they can wash, but usually the features available. Some have multiple levels and cycles and can spin dry, the other end of the spectrum are ones that just agitate. Power requirements vary, but some of these are getting to the level that a solar system and inverter may be able to support the occasional load of laundry.
Then there are manual options. There are manual crank washing machines. Some use a 5 gallon bucket and a plunger (hopefully not one they have been using to unplug their toilets), or hand washing in a sink. More labor intensive, but no power requirements beyond manual labor.
Honestly, I have no idea what the best option is for living on a boat. Energy and water are always an issue, but there is something to be said for convenience. So, if you are a cruiser, what do you do? If you are thinking about cruising, what do you think you may want to do when you need to wash a few things?