When cruising, your contact with other people will be much more limited. When you do meet people, it will also be with plenty of space between you two. This lack of contact and airy contact when it does occur makes it easy to simply not shower!
People who live on land are used to showering at least once a day, if not more often than that. On a cruising boat, where water is brought out to the boat in 5 gallon jugs, water is not used so sparingly! This means that a daily shower would necessitate more frequent water tank fillings, which is much more work for the cruiser.
As always, there is a simple solution to the problem! If you shower more, you need more water. If you shower less, you need less water! We have asked many cruisers and it seems that a weekly shower is the norm. If you feel dirty or smelly in a few days, you will soon go nose blind to it and more days will pass before you realize that it is already shower day again!
When you meet people, the space between you buffers any potential offending odors. The constant breeze also helps keep the air clear of any unwanted scents that may linger around the cruiser. If someone catches a whiff of you and it is soon shower day, you will then receive the much needed slack as they remember that you live on a boat! They might think you smell a bit and figure that you haven't showered yet today, but the truth is that you haven't showered in days and you will get a free pass!
Cruising and showering are two sides of the same coin, but the cruising side of the coin lands up much more often than the sower side of the coin.