This question comes from Kim, who asks: What if there were a lake on the Moon? What would it be like to swim in it?
Presuming that it's sheltered in a regular atmosphere, in some giant dome or something.
This would be so cool. I honestly think swimming on the moon is cool enough that it gives us a pretty good reason to go to the Moon in the first place.
At the very least, it's better than the one Kennedy gave.
Floating would feel about the same on the Moon as on Earth, since how high in the water you float depends only on your body's density compared to the water's, and not the strength of gravity.
Swimming underwater would also feel pretty similar. The inertia of the water is the main source of drag when swimming, and inertia is a property of matter which is independent of gravity.
The top speed of a submerged swimmer would be about the same on the Moon as here – about 2 meters/second. Everything else would be different and way cooler.
The waves would be bigger, the splash fights more intense, and swimmers would be able to jump out of the water like dolphins.
Calculating the height a swimmer can jump out of the water requires taking several different things into account, But the bottom line is that a normal swimmer on the Moon could probably launch themselves a full meter out of the water, and an olympic swimmer like Michael Phelps might manage 2 or 3 meters.
The numbers get even more exciting when we introduce fins. Swimmers wearing monofins can exceed 3 meters per second, which is fast enough for some pretty impressive jumps even on Earth.
