I recently learned that some watches have a "screw-down crown", which to my understanding is made with a threaded crown stem that tightens into a threaded watch case. This seems inconvenient because a user has to loosen the crown, which can be hard to do if the crown is small or if the user's fingers are big, before it can be used for setting the time.
Some watches have similar water resistance ratings, for example, 100 meters, without the need for a screw-down crown. Obviously gaskets under the crown can help achieve some level of water resistance and combining a screw-down crown with gaskets would be even more water resistant. Also obviously, gaskets probably have a life shorter than most of the other components in a watch.
What other kinds of crowns are there that achieve substantial water resistance without relying on either a screw-down crown or gaskets under the crown?